Carbohydrates 

4 kcal/g 

Called the "Fuel Factor"

50-55% from CHO 

Ketone 

Multiple hydroxyl groups 

O

||

R-C-R'

Energy storage 

Coenzymes, DNA, RNA

D Configuration

(of asymmetric carbon farthest from keto group)

Dextrorotatory

-OH on the right 

Rotation of an enantiomer is clockwise

L Configuration 

(of asymmetric carbon farthest from keto group)

Levorotatory 

-OH on the left

Rotation of enantiomer is counterclockwise 

Simple Carbohydrates

Simple sugars with one or two single sugars 

Example. Monosaccharide, Disaccharide

Complex Carbohydrates

Several sugar units

Ex. Oligosaccharides and Polysaccharides 

Sorbitol 

Sugar alcohol from glucose & converted to fructose 

1. Found in berries, cherries, plums, pear

2. Used to make sweeteners - excess can cause diarrhea

Polysaccharides 

Complex CHO's made of many sugar single units joined together by glycosidic bonds

Metabolism 

1. Oxidized via citric acid cyle, TCA, Krebs cycle

2. Excess CHO converted to glycogen

3. Hormonal Control 

4. Catabolic Pathways

Hormonal Controls can: 

1. Raise blood glucose levels - glucagon, epinephrine, glucocorticoids, thyroxine, and growth hormone

2. Lower blood glucose levels - insulin 

Catabolic Pathways 

Breakdown of complex molecules into smaller units

1. Glycolysis, pyruvate oxidation, Krebs cycle and oxidative phosphorylation = "BIG 4"

a. Depends on ATP, ADP, and AMP concentration

b. ATP is high, Big 4 are too low 

c. ATP is low, Big 4 are accelerated 

Carbohydrate Structure 

CHO groups come in two forms: 

Starch - complex 

Sugars - simple

CHO bonds 

Digestible - α

Indigestible - ß 

Straight Chain: 1-4 

Branched Chain: 1-6

Types of Monosaccharides: 

1. Glucose 

2. Fructose 

3. Ribose 

4. Sorbitol 

5. Mannitol 

Glucose 

6-Carbon Molecule

Family: Aldose 

Source: Dextrose, corn syrup 

Fructose 

 AKA: Fruit sugar

6-Carbons 

Family: Ketose 

Source: Fruits, honey 

Ribose

5-Carbons 

Family: Aldose

Source: Nucleic acids 

Mannitol 

Pineapples, olives, and sweet potatoes 

Disaccharides &

Oligosaccharides Types

Maltose

Lactose 

Sucrose 

Trehalose

Maltose 

Bond - Α1-4 

Starch breakdown: Glucose + Glucose 

Lactose 

Bond - Β1-4

Milk: Glucose + Galactose 

Sucrose 

Bond = α-ß1-2

Whiet sugar - Glucose + Fructose 

Trehalose

Source: Mushrooms, yeast 

Polysaccharides 

Cellulose 

Amylose (linear) 

Amylopectin 

Glycogen 

Cellulose 

Bond ß1-4 

Source: Fiber (not digestible)- plants 

Amylose 

Linear amylose 

Bond α1-4 

Source: Plant starch (best source - potatoes)

Amylopectin 

Has less frequent but longer branches than Glycogen 

Bond: α1-4 > α1-6

Source: plant starch (pectin)

Glycogen 

Glycogen is higly branched 

 Bond: α1-4 > α1-6

Animal starch (stored in liver and muscle)

Non-cellulose polysaccharides 

Absorb water, swell, slow emptying of food mass, bind bile acids to cholesterol

Sources: hemicellulose, pectin, gums, mucilages (gum dissolved in juices of plant), and algal substances (seaweed)

Mouth Digestion 

Enyzme: Ptyalin 

Starch is hydrolyzed by ptyalin to - dextrins  - maltose

Stomach 

No digestion 

Small intestine 

Sucrase 

Lactase 

Maltase 

Sucrase 

Sucrase → Sucrose → 

 Gluctose + Fructose

Lactase

Lactase → Lactose → 

 Gluctose + Galactose

Maltase

Maltase → Maltose → 

 Gluctose + Glucose

Conversion glucose 

CO2 & passing electrons to O2

 complete oxidation of sugar 

Lipids 

9 kcal/g 

Bonds between glycerol and fatty acids is an ester bond 

Saturated fatty acids 

No Carbon-carbon double bonds, filled with a H2, heavy, dense solid at room temp

Sources: lard, butter, coconut & palm oil

Monounsaturated fatty acids 

One carbon-carbon double bond, liquid at room temp

Sources: olive oil, peanuts, peanut oil, canola oil, almonds, pecan and avocados

Polyunsaturated fatty acids 

More than one carbon-carbon double bond, liquid at room temp

Sources: sunflower, corn, cottonseed & soybean oils, linoleic, alpha linoleic (essentail aa)

Essential Fatty Acids 

Main building blocks of fats

Linoleic acids

Linolenic acids 

Arachidonic acids 

Linoleic Acid

Omega-6 fatty acid 

Polyunsaturated vegetable oils 

Linolenic

Omega-3 fatty acids 

Arachidonic acid 

becomes essential when linoleic acid

is absent from the diet

Triacylglycerols 

Aka triglycerides 

3 Fatty acids + glycerol (ester bond) 

Phospholipids 

2 Fatty acid, glycerol + phosphate derivatives. 

Found in all cell membranes - lipid bilayer

Fatty Acid Derivatives

Triacylglycerols

Phospholipids 

Cholesterol 

Cholesterol 

Belongs to a group called "sterols"

Requires ATP, Mg & NADPH

Used to make cell membranes, bile salts, & steroid hormones 

Liver converts cholesterol into bile, bile emulsifies fat 

fat + bile = mixed micelle 

Precursor molecules: mevalonate, acetyl coA, squalene & HMG CoA (MASH song)

Allosteric enzyme - HMG CoA reductase 

Lipoproteins

Chylomicron (CM)

VLDL

LDL 

HDL 

Chylomicron

Source: Intestinal mucosa

Function: transports dietary (lipids to body)

Important enzyme - Lipoprotein lipase

Highest % triglyceride 

VLDL 

Source: Liver 

Function: Transports endogenous (lipids from liver to body)

Important enzyme: Lipoprotein lipase 

Lowest trigylceride

LDL 

Source: Liver 

Function: Transports cholesterol (liver to body)

Highest % cholesterol 

HDL 

Source: Liver 

Function: Removes excess "free" cholesterol from the blood 

Important enzyme: LCAT lecithin cholesterol acyl transferase

Lipolysis

Breakdown of Trigylcerids - esters of fatty acids & CoA (called acyl CoA)

Enzyme - lipase 

Beta Oxidation 

Located in the mitochondria 

Function is to cut the fatty acid chain, two carbons at a time to make acetyl CoA for Kreb's 

Requires Carntine to drive/ transports fatty acid chain into mitochondria 

Produces one acetyl CoA, reduces one FAD to FADH2 & reduces NAD to NADH

Odd number of carbons - final piece will be 3-carbons long (propionyl CoA)

Ketogenesis 

Forms ketone bodies as a by-product of beta-oxidation 

Increases in fasting, low carbohydrate diet, diabetes mellitus, & pregancy (esp 3rd trimester)

Ketone bodes: acetoacetate, acetone, & hydroxybutyrate 

Lipogenesis 

Located in the cytoplasm 

Produces fatty acids, two carbons at a time from acetyl CoA

Intermediate - malonyl CoA is the most important 

Requires Acetyl CoA, CO2 & NADPH

Stimulated by ATP & insulin

Inhibited by Ephinephrine and glucagon 

Digestion 

Mouth - lingual lipase 

Small intestine 

Oxidation

Increasing positive charges or loss of negative charges. Removal of H+ ions. 

Reduction

Addition of hydrogens, gain of electrons. 

# of Carbons / Double Bonds of: 

Arachidonic 

LinoLENic 

LinoLEIc

EPA 

20:4

18:3 

18:2 

20:5

Kinase does what? 

Transfers a phosphate

Where does the Kreb's cycle take place? 

Mitochondria 

Where does the Electron Transport Chain take place? 

Inner mitochondria 

What is an example of a ketogenic amino acid? 

Leucine 

Amino Acids are 

The building blocks of protein 

PVT TIM HALL 

Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Arginine, Leucine, Lysine 

Semi-Essential Amino Acids

Histidine, Arginine

Aromatic "ring" 

Phenylalanine, Tryptophan, Tyrosine 

What can Tyrosine be used to treat a patient with? 

Depression 

Basic Type of Amino Acids 

"HAL is a basic kind of guy"

Histidine, Arginine, Lysine

Neutral Amino Acids

"STAG"

Serine

Threonine

Asparagine

Glutamine

Sulfur-Containing Amino Acids 

"MC SULFUR..."

Methionine, Cysteine 

NOT glucogenic amino acids 

Leucine 

Lysine 

Branch Chain Amino Acids

"LIV"

 or Go out on a limb and live!

Leucine

Isoleucine

Valine 

Acidic amino acids 

Glutamate

Aspartate

Aliphatic Chain of Amino Acids 

Listed from less hydrophilic to most hydrophilic 

Glycine

Alanine 

Valine 

Leucine 

Isoleucine 

Amino Acids that aid in Digestion for the Mouth

None - Ptyalin 

Amino Acids that aid in Digestion for the Stomach

Pepsin, HCl, Renin (infancy & childhood only)

Amino Acids that aid in Digestion for the Small Intestine

Trypsin, Chymotrypsin, Carboxypeptidase, Amino peptidase, Dipeptidase 

Amino Acid Metabolism 

Route

Transamination - Oxidative Deamination 

Amino Acid Metabolism 

Removed ammonia

Carried to the urea cycle by Glutamate 

Amino Acid Metabolism 

"Left over" carbon skeletons are either 

1. Glucogenic: form pyruvate / OAA to make glucose

2. Ketogenic: form acetyl CoA or Acetoacetyl CoA to make glucose 

Amino Acid Metabolism 

Three Amino Acids - donate Nitrogen for Purines and Pyrimidines 

Glutamine, Aspartate & Asparagine 

Six Amino Acids to get the muscle to be able to oxidize

"GALVIA"

Glutamate, Aspartate, Leucine, Valine, Isoleucine, Asparagine

 Lactic Acid Cycle / Cori Cycle 

MUSCLE during anaerobic conditions: Glucose broken down by glycolsis - Pyruvate reduced by lactate dehydrogenase - Lactate 

Lactate transported to the liver - Pyruvate via glucogenesis-  glucose. 

*** Consumes total of 4 ATP

Glucose- Alanine Cycle 

Pyruvate can be converted to either Lactate or Alanine

Alanine travels from the muscle through the blood to the liver. Alanine is oxidized and converted back to pyruvate, while ammonia (NH3) is produced and converted into urea. 

Urea Cycle / Ornithine Cycle 

"Ordinarily Careless Crappers Are Also Frivolous About Urination"

Ammonia + Carbon dioxide enters the urea cycle via Carbamoyl phosphate synthetase to produce Carbomyl phosphate

Important intermediates: Ornithine + Carbomyl Phosphate = Citrulline + Aspartate = Argininosuccinate > Fumarate (goes to Krebs Cycle) & Arginine > Urea

Proteins and Peptides 

Peptide Bonds

Peptide bonds are the bonds between amino acids 

 Primary Protein Structure 

Number ad sequence of amino acids; determine the proteins structure 

Secondary Protein Structure 

Two types exist: 

Alpha helix 

Beta Pleated sheet aka "beta bend"

Tertiary Protein Structure

Maximally folded for function to appear as a 3-dimensional structure 

Quarternary Protein Structure 

 Arrangement of multiple folded protein or coiling protein molecules in a multi-subunit complex

Best Ex: hemoglobin with 4 chains 

Amino Acid Key Conversions 

Alanine -- Pyruvate

Glutaine -- Glutamate -- alpha-Ketoglutarate

Asparagine -- Aspartate -- OAA

KEY - AMINO ACID PRECURSORS

Serotonin -- Tryptophan 

GABA -- Glutamate 

Histamine -- Histidine

Creatine -- Glycine/ Arginine

NAD -- Tryptophan 

Enzymes Properties

Function: speed up the reaction 

Specific: one reaction only 

Reaction types: Catabolic (breakdown / generates energy)  & Anabolic (build up / needs energy)

Binding Site: Reactant / substrate attaches

CoFactor / Coenzyme: enzyme + cofactor = holoenzyme & whole thing! 

Apoenzyme: enzyme without cofactor

Regulation of Enzymes 

Rule of thumb: Substrate stimulates a reaction, products inhibit a reaction 

Steroids: regulates rate of enzyme synthesis (at the DNA level)

Zymogen Activation: A zymogen is a protein that becomes an active enzyme when parts are removed (eg. pepsinogen- pepsin) 

Phosphorylation & Dephosphorylation: Participate in control mechanism for cellular metabolism 

Allosteric Site: Area on the enzyme where a compound may bind and change the rate of activity

Kinetics

Reaction velocity proportional to enzyme concentration

All binding sites are "saturated" & reach maximum velocity (Vmax)

Michaelis-Menten constant (Km): Concentration of substrate at which an enzyme yields 1/2 Vmax 

Important Enzyme Families

Kinase: transfers a phosphate (usually from ATP), ATP & Mg2+ (cofactors) ex. Hexokinase

Oxidoreductase: Moves hydrogen, Catabolic: NAD+, FAD

Anabolic: NADP (cofactors), Ex. G-3-P dehydrogenase

Epinephrine (Adrenalin)

Formed - amino acid Tyrosine 

Stimulates - pathways which produce energy

Inhibits - pathways which store energy

Insulin

"Remember ...insulin comes from the Islets of Langerhans  & is made by Beta cells"

Peptide hormone that is secreted by the tail of the pancreas

Stimulates pathways which store energy

Inhibits hormone sensitive lipase

Glucagon 

Peptide hormone secreted by the alpha cells of the pancreas, but has the opposite effect of insulin 

Stimulates glycogenolysis but does not stimulate glycolysis

Function: releases glucose into the blood

Steroid Hormones 

Derivative: Cholesterol

Increase: synthesis of particular enzymes/ proteins 

Produced: In the adrenal cortex

Glucocorticoids: promotes gluconeogenesis, increase protein breakdown, increase Beta oxdiation & ketogenesis: cortisol and cortisone

Mineralcorticoids: Important in regulating electrolyte balance, enhance retention of Na & excretion of K, ammonia & protons (eg. aldosterone)

Gonadocorticoids: "sex" hormones that are responsible for secondary sexual characteristics (puberty)

Male - androgens (testosterone - where free cholesterol is the initial substrate for testosterone synthesis)

Female - Estrogen and progesterone (estradiol, estrone, progesterone)

RATE LIMITING STEPS 

Kreb's Cycle: Isocitrate dehydrogenase 

HMP Shunt: Glucose-6-phosphate dehydrogenase 

Fatty Acid synthesis: Acetyl CoA Carboxylase

Beta Oxidation: Carnitine acyltrasnferase I

Urea Cycle: Carbamoyl phosphate synthetase I 

What happens with NAD and NADH?

NAD: Breaks molecules 

NADH: Builds molecules 

Suffix for:

Amino acid derivative 

Peptide 

Steroid 

-Ine : epinephrine 

- In : Insulin 

- One : Testosterone

Rickets / Osteomalacia may occur if there is a deficiency in what? 

Calcium 

Phosphorus

Vitamin D 

Pernicious Anemia is associated with a deficiency in? 

What vitamines does the Electron transport chain need to function? 

Copper 

Iron 

B2 

B3

What are the 4 D's of Pellagra? 

Which vitamin is needed to prevent pellagra? 

Dementia, death, dermatitis, diarrhea

B3 / Niacin 

**Remember 3 nice men 4 D