Term
| carbohydrates occur as: (2) |
|
Definition
|
|
Term
| functions of carbohydrates: (3) |
|
Definition
-energy storage (sugars and starches)
-structural
-dietary energy (ATP) |
|
|
Term
| monomers of carbohydrates are called ___________. 2 examples. |
|
Definition
| monosaccharides. glucose and fructose |
|
|
Term
| a disaccharide of carbohydrates is the __________ of 2 monomers by ________ linkages. examples are: |
|
Definition
condensation, glycosidic.
examples : sucrose (table), maltose (malt), and lactose (milk) |
|
|
Term
| examples of polysaccharide carbohydrates in plants: (2) |
|
Definition
-cellulose (for the cell wall)
-starch (energy stored) |
|
|
Term
| example of polysaccharide carbohydrate in animals |
|
Definition
|
|
Term
| what is the structure of a fatty acid? |
|
Definition
| hydrophilic head (COOH) and hydrophobic tail (long hydrocarbon chain) |
|
|
Term
| what does hydrophilic mean? |
|
Definition
|
|
Term
| what does hydrophobic mean? |
|
Definition
|
|
Term
| what is the function of fatty acids? (3) |
|
Definition
-long term energy storage (for fats; like hibernating animals)
-hormones (for steroids)
-membranes (the phospholipid bilayer of a cell membrane) |
|
|
Term
| an unsaturated fatty acid has what? What is the difference between a saturated fatty acid and an unsaturated fatty acid? |
|
Definition
unsaturated fatty acid has double bonds (better for you than saturated).
saturated fatty acid has all carbon atoms filled, so it has all the H groups needed. |
|
|
Term
| where are steroids synthesized? |
|
Definition
|
|
Term
| what is the monomer of proteins? |
|
Definition
|
|
Term
| what is the general structure of an amino acid? how many amino acids are there? |
|
Definition
-20 amino acids
-each amino acid differs in its "r" group
-each amino acid has an amino group (NH2), a carboxyl group (COOH), a side "R" group, and a central C atom |
|
|
Term
| what is the polymer of proteins? |
|
Definition
|
|
Term
| what is the bond called that forms between amino acids? |
|
Definition
|
|
Term
| how are polymers of proteins formed? |
|
Definition
| by condensation of many amino acids |
|
|
Term
| when two amino acids combine what is the structure called? |
|
Definition
|
|
Term
| what two groups of 2 different amino acids does a peptide bond form between? |
|
Definition
| a C-N bond found between carboxyl C of one amino acid and amino N of another |
|
|
Term
| what are enzymes? what are their functions? |
|
Definition
| proteins that cataylze reactions |
|
|
Term
| what are examples of structural functions of proteins? (3) |
|
Definition
|
|
Term
| Functions of proteins (6) |
|
Definition
-enzymes (lysozyme and alcohol dehydrogenase)
-structure (collagen, hair)
-storage
-transport (microtubules, muscle proteins)
-immunity
-storage proteins (seeds, milk, egg white) |
|
|
Term
| what is the primary structure of a protein? |
|
Definition
| the unique sequence of amino acids arranged in a long chain |
|
|
Term
| what is the secondary structure of a protein? (2) |
|
Definition
-pattern of hydrogen bonds between amino acids in a long chain
1) alpha helix: hydrogen bonds join the NH group in one peptide bond and the C=O group nearby
2) B pleated sheets: joining of the same NH and C=O bond but amino acids involved are either on different chains or in segments of same chain that bend back and lie close to each other (silk) |
|
|
Term
| what is the tertiary structure of a protein? |
|
Definition
-globular (what most enzymes are)
-held together by a variety of bonds (ionic, hydrogen, disulfide, hydrophobic interactions) |
|
|
Term
| what is the quartenary structure of a protein? |
|
Definition
-made up of several polypeptide chains that must fit together to form a functional protein
-hemoglobin is an example |
|
|
Term
| what is the main protein of connective tissue in animals |
|
Definition
|
|
Term
| what is an actin filament? what does it provide for cells? |
|
Definition
-actin molecule = 1 globular protein
-mechanical support in cells |
|
|
Term
|
Definition
single nucleotide polymorphism
a single amino acid substitution in a protein can cause disease (like sickle cell anemia) |
|
|
Term
| 4 steps to how an enzyme works |
|
Definition
1) enzyme available with empty active site
2) substrate binds to enzyme
3) substrate is converted to products
4) products are released |
|
|
Term
| what do catalysts do? (3) |
|
Definition
-increase the rate of reaction
-lower energy of activation
-react with specific substances called substrates |
|
|
Term
| What is lock and key fit (binding) refer to? |
|
Definition
| -the exact fit of an enzyme (lock) and the substrate (key) when an enzyme binds to an active site |
|
|
Term
|
Definition
| -some enzymes will not bind to substrate unless coenzymes (Ca, Fe) are present |
|
|
Term
| what are the four types of inhibition? |
|
Definition
1) competitive inhibition
2) non competitive inhibition
3) reversible
4) irreversible |
|
|
Term
| what is competitve inhibition? |
|
Definition
| when there are compounds similar to the substrate that compete with the substrate by binding to the enzyme. |
|
|
Term
| What is non competitive inhibition? |
|
Definition
| inactivates crucial groups on enzyme's active site |
|
|
Term
| what is reversible inhibition? |
|
Definition
| the enzyme structure is unaltered |
|
|
Term
| what is irreversible inhibition? |
|
Definition
| when the enzyme structure is altered |
|
|
Term
| what are allosteric enzymes? |
|
Definition
-exist in two or more states because they have two or more binding sites
-change from one shape to another depending on which site(s) is occupied
-binding of molecules to regulatory site changes shape and therefore its activity
-binding of allosteric inhibitors to regulatory site causes distortion of active site --> poor enzyme activity |
|
|
Term
| what are five factors that affect enzyme activity? |
|
Definition
1. inhibitors
2. allosteric enzymes
3. pH
4. temperature
5. hormone or endocrine disrupters |
|
|
Term
| how can pH affect enzymes? |
|
Definition
| -the surrounding pH can change the ionic charges on an enzymes "R" group |
|
|
Term
| at what pH do most enzymes work best? |
|
Definition
|
|
Term
| how does temperature affect enzyme activity? |
|
Definition
| -increases the rate of reaction |
|
|
Term
| what happens to an enzyme when the temperature passes 60 degrees C? |
|
Definition
| -enzyme denaturation: the destruction of the 3D structure |
|
|
Term
| what are hormone or endocrine disrupters? |
|
Definition
-environmental chemicals that affect the function of the endocrine system i.e. they act as imposters of naturally occurring estrogen and other hormones
-DDT |
|
|
Term
| what are the two nucleic acids? |
|
Definition
-deoxyribonucleic acid (DNA)
-ribonucleic acid (RNA) |
|
|
Term
| what is the function of DNA? |
|
Definition
|
|
Term
| what is the function of RNA? |
|
Definition
| -direct the synthesis of proteins (transcription, translation) |
|
|
Term
| what are the monomers of nucleic acids? |
|
Definition
|
|
Term
| what are the three parts that a nucleotide is composed of? |
|
Definition
-a pentose (5 carbon) sugar
-a nitrogenous base
-a phosphate roup |
|
|
Term
| what is the sugar in RNA? |
|
Definition
|
|
Term
| what is the sugar in DNA? |
|
Definition
|
|
Term
| what is the difference in bases between DNA and RNA? |
|
Definition
-DNA has cytosine, thymine, adenine, and guanine
-RNA has cytosine, uracil, adenine, and guanine
-Therefore, DNA has thymine, but RNA has uracil |
|
|
Term
| which bases are pyrimidines? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| what is the backbone of DNA called? |
|
Definition
| the sugar phosphate backbone |
|
|
Term
| what is the structure of DNA? who discovered it? |
|
Definition
-double helix
-Watson and Crick |
|
|
Term
| What is the difference between a dehydration synthesis reaction (condensation reaction) and hydrolosis? |
|
Definition
-condensation joins together two molecules with the LOSS of water
-hydrolosis breaks apart a large molecule into two molecules with the ADDITION of water |
|
|
Term
| why is microscopy importation? what does it provide? |
|
Definition
-important in study of cell structure
-provides enlargement and resolution |
|
|
Term
| Resolution increases with __________ wavelength. |
|
Definition
|
|
Term
| What is a light microscope? |
|
Definition
-enlargement provided by objective lens and ocular lens
-glass lenses
-illumination provided by light |
|
|
Term
| what is a transmission electron microscope (TEM)? |
|
Definition
-illumination provided by electron beam (shorter wavelength)
-very high resolution
-beam passes through specimen
-observation is made under Vacuum so that electrons are prevented from being absorbed by air or deflected |
|
|
Term
| what is a scanning electron microscope? (SEM) |
|
Definition
-electrons do not pass through the specimen
-lower resolution than TEM
-great advantage = great depth of focus (three dimension) |
|
|
Term
| what are the four unique characteristics of eukaryotes? |
|
Definition
1. membrane-bound organelles (ER, Golgi, lysosomes, mitochondria, cell wall (in plants))
2. nucleolus
3. nucleus
3. cytoskeleton (microtubules, intermediate filaments, microfilaments) |
|
|
Term
| Major differences between prokaryotes and eukaryotes |
|
Definition
-prokaryotes: smaller, simpler, most do not have membrane bound organelles--bacteria and archaea
-eukaryotes: larger, more complex, membrane bound organeles -- protists, plants, fungi, and animals |
|
|
Term
| what do plant cells have that animal cells do not? (2) |
|
Definition
|
|
Term
| What do animal cells have that plant cells do not? |
|
Definition
|
|
Term
| what is the largest organelle? |
|
Definition
|
|
Term
| What are the three components of the nucleus? |
|
Definition
1. chromosomes
2. nuclear membrane
3. nucleolus |
|
|
Term
|
Definition
| -contains DNA and histones in nucleosomal configuration; condensed chromosomes |
|
|
Term
| what are nuclear pores and where are they found? |
|
Definition
-found in the nuclear membrane
-allow for the passage of RNA in and out of the nucleus |
|
|
Term
| the nuclear membrane is what kind of membrane? |
|
Definition
| phospholipid bilayer with integrated proteins |
|
|
Term
| nucleoli contain hundreds of copies of only one type of genes. what type of genes are these? |
|
Definition
|
|
Term
| when are the nucleoli most distinctly seen? |
|
Definition
|
|
Term
| each ribosome is composed of how many subunits? |
|
Definition
| two. one large and one small. |
|
|
Term
| the components of ribosomes (2) |
|
Definition
|
|
Term
| where are ribosomes first partially assembled? |
|
Definition
| the nucleoli. and are called pre-ribosomes. |
|
|
Term
| what is the function of ribosomes |
|
Definition
| -translation (protein synthesis) |
|
|
Term
| What are the three aspects of the central dogma? |
|
Definition
1. synthesis of mRNA in the nucleus
2. movement of mRNA into cytoplasm via the nuclear pore
3. syntehsis of protein in the cytoplasm |
|
|
Term
| what is the function of the rough endoplasmic reticulum? |
|
Definition
|
|
Term
| what is the function of the smooth endoplasmic reticulum? |
|
Definition
| -lipid and steroid synthesis (regulate calcium concentration and regulate drug metabolism) |
|
|
Term
| what is the difference between the rough ER and the smooth ER? (structural) |
|
Definition
-rough ER has ribosomes attached to the outer (cytoplasmic) surface
-smooth ER has no attached ribosomes |
|
|
Term
| what are the components of the Golgi complex? |
|
Definition
| -stack of flattened membranous sacs surrounded by a halo of vesicles |
|
|
Term
| what is the function of the Golgi? |
|
Definition
-sorts, modifies, and repackages molecules
-cis (receiving side) and trans (sending off side) |
|
|
Term
| How does the Golgi change the proteins? (2) |
|
Definition
1. removal of amino acids
2. addition of functional groups |
|
|
Term
|
Definition
| -membrane bound sac containing hydrolytic enzymes |
|
|
Term
| what is the function of lysozymes? |
|
Definition
| -DIGESTION of viruses, damaged organelles, cellular macromolecules --> into monomers that are reused by the cell |
|
|
Term
| where does cellular respiration take place? |
|
Definition
|
|
Term
| what is the structure of mitochondria |
|
Definition
-double membrane (internal membrane thrown into folds called CRISTAE)
-contains unique DNA called mtDNA |
|
|
Term
| By what mechanism does mitochondria reproduce? |
|
Definition
|
|
Term
| what is the function of mitochondria |
|
Definition
-ATP production (by aerobic cellular respiration)
-ATP needed to power all chemical reactions in cells |
|
|
Term
| what is the endosymbiotic theory? |
|
Definition
| -the theory that postulates that mitochondria might have once been free-living prokaryotes that became incorprated into eukaryotes establishing a symbiotic relationship. |
|
|
Term
| What features of mitochondria support the endosymbiotic theory? |
|
Definition
-the similarity between mitochondria and prokaryotic protein synthesis machinery
-transcription and translation
-have own DNA
-replicate by binary fission |
|
|
Term
| What is mitochondrial DNA (mtDNA) now used as an indicator of? |
|
Definition
evolutionary divergence in the study of eovlution
better than DNA because rate of mtDNA evolution is faster |
|
|
Term
| what is the structure of peroxisomes? |
|
Definition
-bounded by a single layer membrane
-often have crystalline granulate core (enzyme arrays) |
|
|
Term
| what are the three funtions of peroxisomes? |
|
Definition
-detoxification in the liver
-transfer hydrogen from toxic substances to oxygen producing HYDROGEN PEROXIDE
-some break fatty acids into smaller molecules, which are transported to mitochondria for cellular respiration |
|
|
Term
| what are the three unique plant characteristics? |
|
Definition
| plastids, cell wall, and vacuoles |
|
|
Term
| are plastids descendants of free-living bacteria? |
|
Definition
| possibly, they are found in photosynthetic eukaryotes (plants and protists) |
|
|
Term
| what is the function of plastids? |
|
Definition
| food production and storage |
|
|
Term
| what are the three plastids |
|
Definition
1. chloroplasts
2. chromoplasts
3. amyloplasts |
|
|
Term
|
Definition
-photosynthetic organelles
-CO2 + H2O + light energy = carbohydrate |
|
|
Term
| what is the green pigment contained in chloroplasts? |
|
Definition
|
|
Term
|
Definition
| plastids that synthesize and store yellow and orange pigments |
|
|
Term
|
Definition
| plastids that store starch (potatoes and roots) |
|
|
Term
| what is the function of the cell wall |
|
Definition
-protection and support
-water in cell exerting outward pressure on their walls, cementing together of adjacent cells |
|
|
Term
| what are the components of the cell wall? |
|
Definition
-thick, porous cell walls outside the plasma membrane
-mainly cellulose and other fibers
-flexible |
|
|
Term
| what does porous mean in reference to the cell wall? |
|
Definition
| -allows passage of water and dissolved substances |
|
|
Term
|
Definition
|
|
Term
| what are the functions of vacuoles? |
|
Definition
| -contian fluid, food, pigments, and toxic substances (variety of functions) |
|
|
Term
|
Definition
| -a large central vacuole that is part of the endomembrane system |
|
|
Term
| what are the three types of protein fibers in the cytoskeleton? |
|
Definition
1. microtubules (cilia, flagella, basal body)
2. intermediate filaments
3. microfilaments |
|
|
Term
| what is the function of the cytoskeleton? |
|
Definition
| -provides framework for cell shape and ovement |
|
|
Term
|
Definition
| -hollow tubes made of globular proteins |
|
|
Term
| what are the functions of microtubules? |
|
Definition
-cell shape
-cell motility
-provides tracks on which organelles can move
-spindle movement of chromosomes during cell division |
|
|
Term
| what are cilia and flagella? |
|
Definition
-thread like microtubules grown from a basal body
-a circle of 9 pairs of microtubules
-1 pair in middle |
|
|
Term
|
Definition
-consist of one pair of microtubules at right angles to each other
-these separate to opposite poles providing anchors for mitotic spindle fibers during cell division |
|
|
Term
| what is the function of intermediate filaments? |
|
Definition
-structural support
-maintenace of cell shape |
|
|
Term
| what are the functions of microfilaments? |
|
Definition
-muscle contration
-cytoplasmic sreaming
-endocytosis, exocytosis
-maintenance of or changes in cell shape |
|
|
Term
| what are the three components of the fluid mosaic model? |
|
Definition
-lipids
-proteins
-carbohydrates |
|
|
Term
| what role do lipids play in the fluid mosaic model? |
|
Definition
-phospholipid bilayer
-hydrophilic heads and hydrophobic tails |
|
|
Term
| what role does cholesterol play in the fluid mosaic model? |
|
Definition
| cholesterol reduces fluidity but prevents membrane solidifcation at cold temperatures |
|
|
Term
| what kinds of molecules pass easily through a phospholipid membrane? |
|
Definition
| small and hydrophobic molecules |
|
|
Term
| what are the two types of proteins found in the fluid mosaic model? |
|
Definition
-intrinsic (integral) proteins
-extrinsic (peripheral) proteins |
|
|
Term
| what are intrinsic (integral) proteins?what is their function? |
|
Definition
-these have hydrophobic regions and penetrate the bilayer, extending from one side to the other (like channel proteins)
-their function is to transport large molecules from the outside to the inside of the cell and vice versa (transport proteins) |
|
|
Term
| what are extrinsic (peripheral) proteins? what are their functions? |
|
Definition
-these are found on one surface only
-they lack hydrophobic regions and are not completely embedded in the bilayer
-varied functions: carrier proteins, cell to cell recognition proteins, glycoproteins, receptor proteins, intercellular junctions, and enzymatic proteins |
|
|
Term
| what are proteins that contain carbohydrate molecules called? |
|
Definition
| -glycoproteins (recognition proteins) |
|
|
Term
| what are some examples of signal (cell-cell recognition/glycoprotein) proteins? |
|
Definition
-blood proteins
-human leukocyte antigens
-immunoglobin |
|
|
Term
| What are the six functions of membrane proteins? |
|
Definition
1. Cell recognition and adhesion
2. Transport
3. Membrane proteins
4. Signal transduction
5. Endocytosis and exocytosis
6. Attachment to the cytoskeleton and extracellular matrix |
|
|
Term
| What is homotypic bonding? |
|
Definition
when the same molecule STICKS out of both cells and the exposed surfaces bind to each other (same protein on two cells)
-example = sponge cells |
|
|
Term
| what is heterotypic bonding? |
|
Definition
when different proteins from two types of cells have complementary binding surfaces
-example: different mating type gametes |
|
|
Term
| What are three types of cell recognition and adhesion? |
|
Definition
1. homotypic bonding
2. heterotypic bonding
3. intracellular junctions |
|
|
Term
| What are the four types of intracellular junctions? |
|
Definition
1. tight junctions
2. desmosomes
3. gap junctions
4. plasmodesmata |
|
|
Term
| What are tight junctions? What is their function? |
|
Definition
-seal areas between adjacent epithelial animal cells
-prevent movement of molecules through intracellular membrane spaces
-cannot pass through tight junctions |
|
|
Term
| What are desmosomes? what are their funtion? |
|
Definition
-provide anchoring between cells, permitting material to move around them in the intracellular space
-KERATIN fibers extend through the cytoplasm from one plaque to the other providing great stability
-looks like the clump of half of a button
-found in areas of high stress (cervix cells and elbow cells) |
|
|
Term
| what are gap junctions? what do they allow? |
|
Definition
-protein channels linking adjacent ANIMAL cells
-direct passage of ions and small molecules facilitating communication
-flow of substances from one cell to the next |
|
|
Term
|
Definition
-found in gap junctions
-protein channels linking adjacent cells |
|
|
Term
| what are plasmodesmata? what are their function? |
|
Definition
-strands of cytoplasm connecting some adjacent PLANT cells
-strands pass through gap in cell walls and function as communication bridges
= to gap junctions in animal cells |
|
|
Term
| What are the two types of transport? |
|
Definition
|
|
Term
|
Definition
-type of passive transport
-random movement of SOLUTES (small) towards equilibrium
-net movement from regions of higher concentration to regions of lower concentration |
|
|
Term
| what types of molecules easily cross membranes by diffusion? |
|
Definition
small uncharged molecules
cross by slipping inbetween the hydrophilic heads of the membrane |
|
|
Term
| What is the rate of diffusion dependent on? |
|
Definition
-concentration: the greater the concentration, the faster the substances diffuse
-oxygen, nitrogen, ethanol = fast
-glycerol (large, uncharged) = slow |
|
|
Term
| What types of molecules do not readily pass through membranes? |
|
Definition
| charged and/or polar molecules (amino acids, sugars, ions) because the interior of the membrane is hydrophobic |
|
|
Term
|
Definition
-type of passive transport because no metabolic energy is required
-the diffusion of WATER across membranes |
|
|
Term
| how does the water diffuse in osmosis (from an area of what concetration to what concentration) |
|
Definition
| -water will diffuse from a region of higher concentration (lower concentration of solutes) to a region of lower concentration (higher concentration of solutes) |
|
|
Term
|
Definition
| has equal concentration of solutes |
|
|
Term
| what does hypertonic mean? |
|
Definition
| has higher total solute concentration than the other solution with which it is being compared |
|
|
Term
| what does hypotonic mean? |
|
Definition
| -has lower total solute concentration than the other solution with which it is being compared |
|
|
Term
| what are protein channels? what do they do? |
|
Definition
-integral membrane proteins form channels through the phospholipid bilayer
-channels are lined with POLAR AMINO ACIDS and water on the inside to bind to polar or charged substances and allow them to pass
-when a stimulus binds, the channel protein opens, and the polar substnace diffuses across the membrane
-some channels are gated |
|
|
Term
| what is facilitated diffusion? |
|
Definition
-a carrier protein combines with a specific substance and moves it from one side to the other (DOWN a concentration gradient)
-a carrier molecule transports substances such as glucose |
|
|
Term
| what is active transport? what does it require? |
|
Definition
| -permits molecules to move AGAINST a concentration gradient and requires ATP |
|
|
Term
| what type of transport is a sodium potassium pump? |
|
Definition
|
|
Term
| what is the function of the sodium potassium pump? |
|
Definition
-maintains LOWER concentration of Na+ and Ca2+ INSIDE the cell
-maintains HIGHER concentration of K+ inside the cell
-Na+ transported OUT
-K+ transported IN
****3 Na+ OUT for every 2K+ IN (for each mole of ATP used)
-the pumping is accomplished by transport proteins with two configurations |
|
|
Term
| what are the two classes of transport proteins? |
|
Definition
1. uniports
2. coupled transport systems |
|
|
Term
|
Definition
| -transport proteins that transport ONE type of solute in one diffusion |
|
|
Term
| what are coupled transport systems? what are the two types and what do they do? |
|
Definition
transport proteins that transport TWO OR MORE different solute but neither solute can be moved unless the other is present
1. symport: if the coupled solutes are transported in the SAME direction
2. antiport: if the solutes are transported in OPPOSITE directions (like the sodium potassium pump) |
|
|
Term
| What are the two functions of signal transduction? |
|
Definition
1. information processing
2. energy transformation |
|
|
Term
| how does information processing of signal transduction work? |
|
Definition
-membrane proteins conduct signals (signal molecule) from OUTSIDE the cell that trigger changes inside the cell
-signal binding induces a change in the receptor protein causing some effect INSIDE the cell
-signal molecule outside --> effect inside |
|
|
Term
| how does energy transformation of signal transduction work? |
|
Definition
-membranes of chloroplast and mitochondria are specialized for the transformation of energy
-a membrane protein / pigment absorbs SOLAR energy
-the membrane protein transfers the energy to ADP to form ATP (chemical energy) |
|
|
Term
| What are the three types of endocytosis? |
|
Definition
1. phagocytosis
2. pinocytosis
3. receptor mediated endocytosis |
|
|
Term
| what is the function of endocytosis? |
|
Definition
-transport of LARGE particles
-membrane changes shape, pinching off small sacs and resealing |
|
|
Term
| non-specific types of endocytosis (2) |
|
Definition
phagocytosis and pinocytosis
-the pseudopodia do not choose which LARGER food particles to engulf and digest |
|
|
Term
| what is receptor mediated endocytosis? |
|
Definition
-the food particles first bind to specific protein receptors
-invagination or pits form
-cytoplasmic surface of the pit becomes coated with CLATHRIN
-vesicle is transported to the cytoplasm |
|
|
Term
| What is the 1st law of thermodynamics? |
|
Definition
| Energy cannot be created or destroyed, but it can be transformed from one kind to another |
|
|
Term
| What is the second law of thermodynamics? |
|
Definition
| one usable form of energy cannot be completely converted to another usable form; that is, in every energy transaction, useful energy decreaes |
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