Term
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Definition
| An enzyme without its cofactor |
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Term
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Definition
| Cataclytically active enzyme |
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Term
| A reaction can take place spontaneously only if ΔG is - or +? |
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Definition
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Term
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Definition
| Least stable and most-seldom-occurring species along the reaction pathway |
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Term
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Definition
| The region of the enzyme that binds the subtrates and cofactor |
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Term
| Michaelis-Menten equation |
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Definition
V0=Vmax x [S]/[S]+KM
KM=k-1+k-2/k1 |
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Term
| An alcohol reacts with a ketone to form an ___? |
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Definition
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Term
| An alcohol reacts with an aldehyde in carbohydrates to form an ___? |
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Definition
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Term
| α (alpha) designation of a cyclic carbohydrate |
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Definition
| The hydroxyl group on the anomeric carbon points in the opposite direction as the hydroxyl group on Carbon 2 |
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Term
| β (beta) designation of cyclic carbohydrate |
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Definition
| The hydroxyl group on the anomeric carbon points in the same direction as the hydroxyl group on Carbon 2 |
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Term
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Definition
| The anomeric carbon atom of a sugar is linked to the nitrogen atom of an amine |
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Term
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Definition
| Bond between C1 of one sugar and C4 of another |
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Term
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Definition
| Enzyme which catalyzes the formation of glycosidic bonds |
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Term
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Definition
| Consists of two sugars joined by an O-glycosidic bond |
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Term
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Definition
| The most common homopolymer in animal cells; the storage form of glucose |
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Term
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Definition
| Storage form of glucose in plant cells |
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Term
| Difference between α and β 1,4 linked polysaccharide structure |
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Definition
alpha -- favor bent structures, which are more suitable for storage (starch & glycogen)
beta -- favor straight chains, which are optimal for structural purposes (cellulose) |
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Term
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Definition
| Proteins attached to a specific polysaccharide called glycosaminoglycan |
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Term
| Fuctions of proteoglycan (4) |
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Definition
1) Lubricants in connective tissue
2) Structural component in connective tissue
3) Mediate adhesion of cells to extracellular matrix
4) Bind factrs that stimulate cell proliferation |
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Term
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Definition
| Carbohydrates connected to proteins |
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Term
| Protein residues to which carbohydrates bind |
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Definition
| Aspargine, serine, or threonine |
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Term
| Advantage of varying blood types in humans (ABO) |
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Definition
| Prevents mimicry of human carbohydrate structure by pathogenic microorganisms |
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Term
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Definition
| Carbohydrate-binding proteins which facilitate cell-to-cell contact |
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Term
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Definition
| Water-insoluble molecules that are highly soluble in organic solvents |
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Term
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Definition
| Simplest type of lipid; most commonly used as a fuel |
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Term
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Definition
| Storage form of fatty acid |
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Term
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Definition
| Membrane lipids consist of fatty acids attached to a scaffold that also bears a charged phosphoryl group, creating a macromolecule with a polar head and nonpolar tail |
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Term
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Definition
| Bound to carbohydrates and are important membrane constituents |
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Term
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Definition
| Polycyclic hydrocarbons that function as hormones that control a variety of physiological functions |
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Term
| ω carbon atom in fatty acids |
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Definition
| Last carbon in the carbon chain that is always a methyl group |
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Term
| Configuration of most double bonds in fatty acids |
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Definition
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Term
| Presence of cis double bond in fatty acid does what? |
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Definition
| Kinks the hydrocarbon chain and makes tight packing between the chains impossible |
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Term
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Definition
| Trans double bond configuration allows for tight packing of hydrocarbon chains and can cause rigidity |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Three fatty acids attached to a glycerol molecule; fatty acid storage |
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Term
| Bond by which glycerol and fatty acids are joined in triacylglycerols |
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Definition
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Term
| Fat storage vs carbohydrate storage |
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Definition
| 1g fat stores 6x more energy than 1g carbohydrates |
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Term
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Definition
| Major accumulation of triacylglycerols |
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Term
| Four components of a phospholipid |
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Definition
1) One or more fatty acids
2) A platform to which the fatty acids are attached (glycerol or sphingocine)
3) A phosphate
4) Alcohol attached to the phosphate
4) |
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Term
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Definition
| Phosphlipids derived from glycerol |
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Term
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Definition
| Sphingosine; an 18-carbon amino alcohol unsaturate hydrocarbon chain |
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Term
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Definition
| Phospholipids built on a sphingosine backbone |
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Term
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Definition
| Common sphingolipid found in membranes, especially in the myelin sheath surrounding nerve axons |
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Term
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Definition
| Sugar-containing lipids found in animal cell membranes with unknown function; derived from sphingosine |
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Term
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Definition
| Simplest glycolipid containing a single sugar residue, either glucose or galactose |
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Term
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Definition
Complex glycolipid that contains branched chains of sugar residues (up to 7)
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Term
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Definition
| Asymmetric orientation in membranes with sugar residues on the extracellular side of the membrane |
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Term
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Definition
Tetracyclic ring structure: steroid nucleus
Three cyclohexane rings and a cyclopentane ring joined together |
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Term
| Membrane composition of archaea |
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Definition
Fatty acid chaines joined to glycerol by ether linkages (rather than ester)
Alkyl chains are branched rather than linear |
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Term
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Definition
| Contain both hydrophobic and hydrophilic regions (membrane lipids) |
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Term
| Integral membrane proteins |
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Definition
| Proteins embedded in the hydrocarbon chains of membrane lipids |
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Term
| Peripheral membrane proteins |
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Definition
| Proteins that are primarily bound to the head groups of the lipids in the cell membrane |
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Term
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Definition
| Uses light energy to transport protons from inside the cell to the outside, generating a proton gradient used to form ATP |
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Term
| Polarity of membrane spanning alpha helices |
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Definition
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Term
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Definition
| Composed mostly of beta strands that create a single beta sheet which curls to form a hollow cylinder (pore) |
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Term
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Definition
Outside surface of porin is nonpolar (interacts with membrane)
Inside surface is hydrophilic (interacts with water) |
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Term
| Lateral diffusion in lipid membranes |
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Definition
| The rapid lateral movement of membrane proteins which has been visualized with the used of fluorescence microscopy and photobleaching |
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Term
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Definition
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Term
| Transverse diffusion of lipid molecules |
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Definition
| Flip-flopping of lipid molecules; once in several hours (very slow) |
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Term
| Key modulator of membrane fluidity in animals |
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Definition
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Term
| Cholesterol in lipid membranes |
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Definition
| Disrupts the tight packing of fatty acid chains |
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Term
| Two factors which determine whether a small molecule will cross a membrane |
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Definition
1) The concentration gradient of the molecule across the membrane
2) The molecule's solubility in the hydrophobic environment of the membrane |
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Term
| Na+ K+ ATPase -- How does it work? |
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Definition
| The hydrolysis of ATP by the pump provides the energy needed for the active transport of three Na+ ions out of the cell and two K+ ions into the cell, generating the gradients; ATP-driven pump |
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Term
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Definition
| Couple the downhill flow of one species to the uphill flow of another in the opposite direction across the membrane |
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Term
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Definition
| Use the flow of one species to drive the flow of a different species in the same direction across the membrane |
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Term
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Definition
| Membrane proteins that pump ions or molecules uphill by coupling with the downhill flow of a different molecule |
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Term
| Example of secondary transport -- Na+/K+ & Na+/glucose |
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Definition
| The antiporter Na+Ka+ ATPase pumps 3 Na+ ions out and 2 K+ in by hydrolyzing ATP. The Na+ gradient on the outside of the cell drives the Na+/glucose symporter to bring Na+ and glucose into the cell |
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Term
Potassium selectivity filter function/mechanism
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Definition
| Potassium gives up its hydration shell to interact with the oxygen atoms of the carbonyl groups of the 5 amino acid residues. Energy cost of dehydrating K+ is made up by the interactions with the selectivity filter, so dehydration is favorable |
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Term
| Why can't Na+ fit through K+ channel? |
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Definition
| The high energetic cost of dehydrating Na+ ions would not be recovered. The K+ channel does not closely interact with the sodium ions, which must stay hydrated and hence cannot pass through the channel |
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Term
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Definition
| Proteolytic enzyme in the stomach |
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Term
| Pancreatic secretion of NaHCO3 |
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Definition
| Neutralizes the pH of the food as it leaves the acidic stomach and enters the small intestine |
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Term
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Definition
| Inactive precursor to enzyme |
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Term
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Definition
| Released by the cells of the small intestine in reponse to the low pH of the food |
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Term
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Definition
| Hormone secreted by the cells of the small intestine in response to the oligopeptide products of pepsin digestion |
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Term
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Definition
| Activates trypsinogen into trypsin, which activates the remaining pancreatic zymogens |
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Term
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Definition
| Digests branched holopolymers of glucose (starch & glycogen) by cleaving the α-1,4 bonds, but not the α-1,6 |
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Term
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Definition
| Combination of lipid droplets and water that leaves the stomach |
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Term
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Definition
| Enzymes secreted by the pancreas which degrade triacylglycerids into fatty acids and monoacylgycerol |
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Term
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Definition
| The structure in which free fatty acids and monoacylglycerol is carried to the intestinal epithelium and absorbed across the plasma membrane |
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Term
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Definition
| Lipoprotein transport particles that are formed then triacylglycerides are resynthesized from fatty acids and the monoacylglycerol in the mucosal cell. They are released into the lymph system. |
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Term
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Definition
| Adenine nucleotide, a ribose, and a triphosphate unit (two phosphoanhydride bonds) |
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Term
| Phosphoanhydride bond formation |
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Definition
| Forms between two phosphoryl groups accompanied by the loss of a molecule of water |
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Term
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Definition
| Free energy is released when ATP is hydrolyzed to ADP/Pi or AMP/PPi |
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Term
| Factors affecting high phosphoryl transfer potential (3) |
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Definition
1) Electrostatic repulsion is reduced when ATP is hydrolyzed
2) ADP and Pi have greater resonance stability than ATP
3) More water can bind to ADP than ATP; hydration stabilizes the molecule |
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Term
| Amount of ATP present in human vs amount consumed in 24 hours |
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Definition
| 100g present, 40 kg consumed |
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Term
| Carbon dioxide vs methane -- which has more energy? |
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Definition
| Methane - the more reduced carbon contains more energy. Fats are more efficient fuel source than carbohydrates because they are more reduced |
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Term
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Definition
Trapped as high phosphoryl transer potential compound, then used to form ATP.
1,3-BPG + ADP --> 3PG + ATP |
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Term
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Definition
Nicotinamide adenine dinucleotide - major electron carrier in oxidation of fuel molecules
Derived from niacin
R-CHOH-R' + NAD+ <---> R-C=O-R' + NADH + H+ |
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Term
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Definition
Flavin adenine dinucleotide in its oxidized form
Consists of riboflavin & ADP unit
Reduced forms: FADH2
R-CH3-CH3-R' + FAD <---> R-CH=CH-R' + FADH2 |
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Term
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Definition
| Reducing power is needed in addition to ATP to form the product |
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Term
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Definition
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Term
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Definition
Terminal sulfhydryl group
Acyl groups are linked to the sulfhydryl group by thioester bonds |
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Term
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Definition
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Term
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Definition
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Term
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Definition
B3
NADH & NADPH vitamin precursor |
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Term
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Definition
B1
Coenzyme: thiamine pyrophosphate (TPP) |
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Term
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Definition
| ATP-dependent carboxylation and carboxyl-group transfer |
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Term
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Definition
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Term
| Irreversible reactions of glycolysis |
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Definition
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Term
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Definition
| C6H12O6 + 6O2 --> 6CO2 + 6H2O + 2805 kJ/mol |
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Term
| Importance of Reaction 3 of glycolysis |
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Definition
| Product (G6P) can only be used for glycolysis so all of this product is funneled into this pathway |
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Term
| Steps of glycolysis ATP spent/ gained |
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Definition
Steps 1 & 3 -- 2 ATP spent
Steps 7 & 10 -- 4 ATP gained
2 ATP total gained
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Term
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Definition
Ratio of ATP: AMP
High energy charge if [ATP] > [AMP]
Low energy charge if [ATP] < [AMP] |
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Term
| PFK as key regulatory step of glycolysis |
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Definition
Citrate is the first product of the citric acid cycle and inhibits PFK
Citric acid cycle is more efficient and produces more ATP than glycolysis, so if this system is running glycolysis is unneccessary. |
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Term
| High concentration of ___ inhibits phosphofructokinase, pyruvate kinase, & hexokinase by allosterically binding to the enzymes |
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Definition
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Term
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Definition
| Phosphorylates C6 of glucose |
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Term
| Phosphoglucose isomerase function |
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Definition
| Converts glucose into fructose (aldose to ketose) |
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Term
| Phosphofructokinase function |
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Definition
| Phosphorylates F6P into 1,6-BP |
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Term
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Definition
| Cleaves 1,6-BP into DHAP & GAP |
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Term
| Triose phosphate isomerase function |
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Definition
| Converts DHAP into GAP (ketone to aldehyde) |
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Term
| Glyceraldehyde 3-phosphate dehydrogenase function |
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Definition
| Phosphorylates the carbonyl carbon of GAP |
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Term
| Phosphoglycerate kinase function |
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Definition
| Removes phosphoryl group from carbonyl carbon, leaving a carboxylic acid |
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Term
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Definition
| Shifts phosphoryl group to C2 and hydroxyl group to C3 (3-PG to 2-PG) |
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Term
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Definition
| Dehydrates 2-PG to enol (phosphoenolpyruvate -- PEP) |
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Term
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Definition
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Term
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Definition
Michaelis constant -- unique to each enzyme ad is independent of enzyme concentration
Describes the properties of enzyme-substrate interaction and will vary if an enzyme uses several substrates |
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Term
| Competetive inhibition double reciprocal graph |
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Definition
| Lines representing presence & absence of inhibitor will have the same y-intercept |
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Term
| Noncompetetive inhibition double reciprocal graph |
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Definition
| Lines will have the same x-intercept |
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Term
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Definition
| Binding model for enzyme and substrate where enzyme changes shape |
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Term
| Enzymes facilitate formation of ___? |
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Definition
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Term
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Definition
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Term
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Definition
|
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Term
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Definition
| Shifts T-R equilibrium toward R state |
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Term
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Definition
| Shifts T-R equilibrium toward the T state |
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Term
| Form of inhibition can be overcome by increasing [S] |
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Definition
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Term
| Form of inhibition that lowers [functional enzyme] |
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Definition
| Noncompetetive inhibition |
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Term
| Enzyme that has a large hydrophobic S1 pocket |
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Definition
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Term
| Catalytic triad in serine proteases |
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Definition
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Term
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Definition
| Stabilizes tetrahedral intermediate in peptide cleavage |
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Term
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Definition
| Two sugars that differ in stereochemistry around only 1 chiral center |
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Term
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Definition
| New chiral center formed when cyclic hemiacetal is formed |
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Term
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Definition
| Type of plot that can be used to predict the presence of transmembrane alpha helices |
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Term
| Toxin that inhibits sodium channel |
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Definition
| Tetrodotoxin (Japanese puffer fish) |
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Term
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Definition
| Type of transport driven by the hydrolysis of ATP |
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Term
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Definition
| Molecule that has both hydrophilic and hydrophobic regions |
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Term
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Definition
| Disaccharide of glucose and galactose |
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Term
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Definition
| Pancreatic enzym that responds to low blood sugar |
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Term
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Definition
| Alternate form of an enzyme |
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Term
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Definition
| Product of enzymatic reaction inhibits the reaction |
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