Metabolism

Question 1

What are part of STORAGE polysaccharides? What kind of linkages

Answer 1

Starches (a1,4- linkages)
- Amylose: linear
- Amylopectin: branched
- We have amylase that digest starch

Glycogen
- storage for animals

Question 2

What are part of STRUCTURAL polysaccharides? type of linkage?

Answer 2

Cellulose (B1,4-linkages)
- humans cannot break this down
- Good for GI movement

Chitin

Question 3

What is fat and cholesterol important for in our body?

Answer 3

• important for PM
• Precursor molecule for steroid hormones and bile salts

Question 4

How many essential AA do infants vs adults need?

Answer 4

infant = 10 (don’t make enough histidine and arginine)
Adult = 8

Question 5

Differentiate between the fat-soluble vitamins and water-soluble vitamins

Answer 5

Fat-soluble
- Need aid of fat digestion
- ADEK
- Except K is stored in the body

Water-soluble
- Absorbed in GI tract
- B-complex

Question 6

Which vitamins are made in the body?

Answer 6

Vit D
Vit B and K (intestinal bacteria)

Question 7

Which vitamins act in an antioxidant cascade?

Answer 7

ACE

Question 8

Differentiate between Anabolsim and Catabolism

Answer 8

Anabolism
- produces larger molecules from smaller ones

Canadbolism
- break down complex structures

Question 9

What are the 3 general stages of metabolism? What are their major pathways?

Answer 9

Stage 1: digestion and absorption (breakdown)

Stage 2: Anabolic pathway into proteins, lipids etcc or catabolic pathway breaken down into pyruvate and acetyl CoA
- glycolysis

stage 3: Catabolic formation of energy
- citric acid cycle and oxidative phopshorylation

Question 10

what is the overall THEORETICAL ATP produced?

Answer 10

36

Question 11

What is the total and NET ATP of glycolysis? How much does it produce? What else does it produce

Answer 11

Produce 4, use 2 = NET 2 ATP

2 NADH
2 Pyruvic acid

Question 12

How much NADH, FADH2, CO2, ATP is produced in kreb cycle per Acetyl CoA? Per glucose molecule

Answer 12

3 NADH
1 FADH2
2 CO2
1 ATP

Per glucose (x2)

Question 13

What is the only pathway that directly uses Oxygen?

Answer 13

Electron transport chain

Question 14

Which complex does NADH feed into? FADH2? What is the general trend in free energy in the ETC and oxidative phosphorylation?

Answer 14

NADH= complex 1
FADH2 = complex 2

Drop in free energy as the complexes pump H+ ions into cytoplasm

Question 15

What is the role of ATP synthase?

Answer 15

• Pumps H+ ions into mitochondria

Question 16

What are the 4 words in each step of the ATP synthase mechanism

Answer 16

1. Stator
2. Rotor
3. Rod
4. Knob

Question 17

What does 1 NADH and 1 FADH2 yield in ATP synthase

Answer 17

NADH= 2.5 ATP
FADH2 = 1.5 ATP
- ETC directly metabolizes there NOT ATP synthase

Question 18

What is the TOTAL NET ATP made? how many NADH and FADH2 are produced total?

Answer 18

30 ATP

10 NADH
2 FADH2

Question 19

Differentiate between glycogenesis and glycogenolysis. When is each pathway used? What is it stimulated by?

Answer 19

glycoGENESIS
- formation of glycogen
- When BG levels are high
- stimulated by insulin

GlycoGENOLYSIS
- breakdown of glycogen
- When BG levels are low
- stimulated by glucagon

Question 20

What are the 2 tissue sharing glycogen? What is the 1 trapped glycogen?

Answer 20

2 sharing: liver + kidney cells
1 trapped: muscle

Question 21

Purpose of glyconeogenesis

Answer 21

Makes new glucose molecules from pyruvates
- maintains BG levels for the brain during fasting

Question 22

Differentiate between triglycerides and its glycerol and fatty acids components?

Answer 22

Triglycerides do all metabolism pathways
- oxidized for energy

• Glycerol enters into glycolysis (produces acetyl coA)
• Fatty acids alone use beta-oxidation for krebs cycle

Question 23

What is they key molecule for conversions in protein metabolism?

Answer 23

Glutamic acid

Question 24

What are the 3 key steps in protein metabolism? Describe them briefly TOK

Answer 24

1. Transamination
   - AAs transfer amine group from a-ketoglutarate acid to form glutamic acid (glutamate)
2. Oxidative deamination
   - takes NH3 off glutamic acid to regenerate a-ketoglutarate
3. Keto acid modification
   - form AA to be oxidized in krebs cycle or converted to ketones or glucose

Question 25

Differentiate between absorptive and postabsorptive states

Answer 25

Absorptive - for 4 hours during and after a meal Postabsorptive - when GI is empt and energy is supplied by body reserves - either make glucose available or save glucose for brain

Question 26

How does insulin help in absorptive state of metabolism (2)

Answer 26

1. Increases protein synthesis 2. Converts glucose to - ATP - Fatty acids/glycerol - Glycogen

Question 27

What are sources of new glucose in postabsorptive state

Answer 27

1. Glycogenolysis in LIVER: first used 2. Glycogenolysis in SKELETAL MUSCLE 3. Lipolysis in adipose tissue and liver 4. Catabolism of cellular protein

Question 28

What is in greatest quantity of the following lipoproteins: Chylomicron VLDL LDL HDL

Answer 28

Chylomicron: triglyceride VLDL: triglycerides LDL: Cholesterol HDL: protein

Question 29

What do each of the following lipoproteins do: Chylomicron VLDL LDL HDL

Answer 29

Chylomicron - comes from intestine - packages TG to take to liver through LPL enzyme VLDL - transport TG from the liver to peripheral tissues LDL - Once TG are unloaded, the VLDL residues are converted to LDLs (cholesterol rich) - Transports cholesterol to peripheral tissues HDL - scoop up and transport excess cholesterol from peripheral tissues back to liver for degredation - also pulls cholesterol from arterial wall - LCAT enzyme help make this

Question 30

What is cholesterol excreted as in the end?

Answer 30

- bile salts - precursor for steroid hormones

Question 31

Differentiate between NPY/AgRP and POMC/CART neurons

Answer 31

NPY/AgRP - enhance appetite - reducing metabolism POMC/CART - suppress appetite

Question 32

What is the 4 mechanisms of heat exchange? which is the most important contributer?

Answer 32

1. Radiation (most important contributor) 2. Conduction 3. Convection 4. Evaporation

Question 33

Differentiate between heat-induced exhaustion and heat stroke.

Answer 33

Heat-induced exhaustion: COLLAPSE during or following vigorous exercise (+extreme sweating) * Mental confusion/fainting due to dehydration + low BP ○ If not cooled/rehydrated: can progress to heat stroke Heat stroke: normal heat-loss processes become ineffective * @ core temp of 40.6C * Increased metabolic rate as a result * Skin is hot/dry - NO SWEATING Organ damage -> death possible