Metabolism

Question 1

Catabolism def

Answer 1

Breaking down larger molecules to release free energy and small molecules

Question 2

What is the energy from catabolism used for (2)

Answer 2

1. Drive cellular processes
2. Build molecules

Question 3

Anabolism def

Answer 3

Using energy to build cell components

Question 4

Anabolism role in disorder

Answer 4

Reduce entropy to create order

Question 5

Metabolism def

Answer 5

Balance between catabolism and anabolism

Question 6

What 4 biomolecules make up the human diet

Answer 6

Proteins, nucleic acid, polysaccharides and fats

Question 7

Digestion reduces these 4 biomolecules to what monomers

Answer 7

Amino acids, nucleotides, monosaccharides, fatty acids

Question 8

Amylases

Answer 8

Starch enzymes that are Hydrolases

Question 9

How do amylases work?

Answer 9

break the bond connecting glucose polymers to monomeric carbohydrates

Question 10

What digests starch

Answer 10

Amylases

Question 11

What digests proteins

Answer 11

Proteases

Question 12

How do proteases work?

Answer 12

Hydrolysis peptide bonds to release AA’s

Question 13

What are Fatty acids digested by?

Answer 13

Lipases

Question 14

How are proteins degraded inside the cell

Answer 14

By lysosome

Question 15

What is a lysosome

Answer 15

Organelle constraining proteases and hydrolytic enzymes

Question 16

Why do proteins need to be degraded?

Answer 16

Because the are abnormal or because their concentration must be regulated

Question 17

What type of proteins do lysosomes degrade?

Answer 17

Extracellular or degradative enzymes

Question 18

How are proteins degraded inside the cells?

Answer 18

By the proteasome core

Question 19

What is a proteasome?

Answer 19

Barrel shaped multisubunit protein complex (protease) in the cytoplasm that targets intracellular proteins

Question 20

What is ubiquitin

Answer 20

A small protein that is transferred to the Lys side chain of the target protein so it can be degregated

Question 21

How do ubiquitins degrade proteins

Answer 21

Once 4 ubiquitins are added, the polypeptide is unfolded and enters the proteasome; active sites than cleave into small pepetides

Question 22

What assists ubiquitins in unfolding the protein

Answer 22

ATP hydrolysis (ATP —> ADP +P)

Question 23

Role of Vitamin C

Answer 23

Antioxidant and a cofactor for the enzyme that hydroxylates proline residues in collagen

Question 24

Vitamin C deficiency

Answer 24

Scurvy

Question 25

Vitamin C deficiency

Answer 25

Scurvy

Question 26

What is vitamin B1

Answer 26

Thiamine

Question 27

What is thiamine

Answer 27

A cofactor for the pyruvate dehydrogenase complex and a-ketoglutarate dehydrogenase

Question 28

What is thiamine

Answer 28

A cofactor for the pyruvate dehydrogenase complex and a-ketoglutarate dehydrogenase

Question 29

What is a B1 deficiency

Answer 29

Beriberi: Weakness and leg swelling

Question 30

What is a B1 deficiency

Answer 30

Beriberi: Weakness and leg swelling

Question 31

What is B3

Answer 31

Niacin

Question 32

Niacin

Answer 32

Precursor for NADP+ and NADPH

Question 33

What does a B3 deficiency lead to?

Answer 33

Pellagra: 4 D’s (diarrhea, dermatitis, dementia and death)

Question 34

Nicotinamine adenine dinucleotide (NAD+/NADH)

Answer 34

Water soluble 2 e- carrier

Question 35

What is the significance of the phosphorylated form (NADP+/NADPH)

Answer 35

Used as a redox cofactor in biosynthetic pathways (NADP+ is oxidized and NADPH is reduced)

Question 36

Ubiquinone (Coenzyme Q)

Answer 36

Mobile electron carrier that receives e- from a prosthetic group; Lipid soluble 1 e- (GH) or 2 e- (QH2) carrier

Question 37

What is B2

Answer 37

Riboflavin

Question 38

Riboflavin

Answer 38

Precursor to forming flavins

Question 39

Flavins

Answer 39

Prosthetic group that can carry 1 e- or 2 e-

Question 40

How are fatty acids stored

Answer 40

As triglycerides

Question 41

How is glucose stored

Answer 41

In the liver and muscles as glycogen

Question 42

What bonds store energy in reduced cofactors?

Answer 42

Phosphoanhydride bonds (ATP) or thioester bonds (acetyl CoA)

Question 43

What happens to excess Amino Acids?

Answer 43

Can be broken down and converted to carbohydrate to be stored as glycogen or as acetyl units and stored as fat

Question 44

How does the liver break down glycogen to release glucose?

Answer 44

Catalyzed by glycogen phosphorylase ; phosphate removed before the release in the blood

Question 45

Catabolism involves doing what to carbon

Answer 45

Oxidizing carbon; replaces C-H with C-O

Question 46

Anabolism involves doing what to carbon

Answer 46

Reducing carbon; replacing C-O with C-H

Question 47

How are electrons passed in oxidation?

Answer 47

Passed as an H atom (proton and 1 e-) or as a H- (hydride; proton and 2 e-)

Question 48

Oxidation

Answer 48

Loss of electrons

Question 49

Reduction

Answer 49

Gain of electrons

Question 50

Cofactors

Answer 50

Temporary carriers of e- such as NAD+ or NADP+ (oxidized form)

Question 51

Metabolites

Answer 51

2-3 carbon intermediates that are products of catabolic pathways and precursors for anabolic pathways

Question 52

What occurs at equilibrium

Answer 52

No net chance in the concentration

Question 53

What occurs when the system is not at equilibrium?

Answer 53

Reactants move to reach equilibrium values

Question 54

Delta G^o’

Answer 54

Standard free energy for a reaction in STP;

Question 55

Delta G with no superscripts

Answer 55

Actual change in the living cell

Question 56

What is the purpose of ATP hydrolysis?

Answer 56

Products of hydrolysis are more stable than reactants because the negative charges are dispersed; products have higher resonance stabilization (greater deloactization of electrons)

Question 57

How are metabolic pathways often regulated

Answer 57

At steps with very negative delta G (irreversible)

Question 58

What occurs at steps with a delta G near zero

Answer 58

They are reversible and the direction of the net rxn depends on the concentration of reactants and products

Question 59

When are irreversible steps most likely to occur?

Answer 59

Early in a metabolic pathway to commit a metabolite to the pathway

Question 60

What is used in chemical rxns to make the overall process favorable

Answer 60

Energy currency