NDFS 200

Question 1

vitamins synthesized

Answer 1

-cannot be synthesized by the body
-must be associated with a deficiency-related

Question 2

stages of converting food to energy

Answer 2

1. digestion: breakdown of complex molecules to their component building blocks
2. conversion of building blocks to acetyl-CoA (or other simple intermediates)
3. Metabolsims of acetyl-CoA to CO2 and formation of ATP

Question 3

metabolism

Answer 3

all net reactions

Question 4

anabolic

Answer 4

build larger molecules

Question 5

catabolic

Answer 5

breaks down larger molecules

Question 6

adenosine triphosphate (ATP)

Answer 6

-gnerally accepted energy storage molecule
-contains nucleotide base adenosine, ribose and three phosphates
-energy released by hydrolyzing phosphates

Question 7

how much ATP is in the body?

Answer 7

-100 g
-body resynthesizes 40 kg/day

Question 8

redox reactions

Answer 8

-carbohydrates, amino acids, and fats are oxidized to produce ATP

Question 9

oxidation

Answer 9

when a molecule/atom loses one or more electrons

Question 10

reduction

Answer 10

when a molecule/atom gains one or more electrons

Question 11

what vitamins are key in biologic redox reactions?

Answer 11

niacin and riboflavin

Question 12

what is produced by cellular respiration?

Answer 12

ATP

Question 13

what does respiration remove from macronutrients?

Answer 13

electrons

Question 14

carbohydrate catabolism overview

Answer 14

-glycolysis
-bridge reaction
-citric acid cycle
-electron transport chain

Question 15

glycolysis

Answer 15

-glucose is converted to pyruvate
-requires 2 ATPs for a activation
-Produces 4 ATPs (Net 2 ATPs) and 2 NADH

Question 16

bridge reaction

Answer 16

-pyruvate dehydrogenase
-this step is irreversible
-requires 4 B-vitamins
- Niacin
-Riboflavin
-thiamin
-pantothenic acid

Question 17

citric acid cycle

Answer 17

-acetyl CoA reacts with oxaloacetate to form citrate
-takes 2 turns to metabolize 1 molecule of glucose
-yeilds:
6 NADH
2FADH2
2 GTP (converted to a

Question 18

Electron transport chain

Answer 18

-90% of the ATP produced by glucose catabolism is by the ETC
-transfer electrons to pump hydrogens and form a proton gradient that can then be used to form ATP
-requires iron and copper
-ultimately oxygen accepts the electrons and is reduced to form water

Question 19

Anaerobic Respiration

Answer 19

-pyruvate is converted to lactate
-recycled NADH to NAD to enable further glycolysis

Question 20

Cori Cycle

Answer 20

1. in the absence of oxygen, muscle produces lactate from pyruvate
2. lactate leaves the muscle via blood and enters the liver
3. liver enzymes convert lactate to glucose using ATP
4. glucose returns to the muscle

Question 21

anaerobic metabolisms

Answer 21

-yeilds only 5% of potential ATP from glucose
-concentration of NAD drops
-to maintain glycolysis, NAD is regenerated
-pyruvate is converted to lactate (muscle fatigue)
-produces a net f 2 ATP, 2 NADH+H+

Question 22

aerobic metabolism

Answer 22

-yeilds 40% of potential energy from glucose
-requires sufficient oxygen, more ATP produced
-leads to pyruvate, then to TCA and ETS to CO2, H2O

Question 23

Sources of fatty acids

Answer 23

-dietary
-from adipose tissue
-hormone-sensitive lipase

Question 24

fatty acid transport

Answer 24

-into the cell through passive diffusion
-inot mitochondria by covalent linkage to carnitine

Question 25

beta-oxidation

Answer 25

-activation of fatty acid by attaching CoA -hydrolyze ATP to AMP and pyrophosphate

Question 26

beta oxidation overview

Answer 26

-oxidize -hydrate -oxidize -hydrolyze

Question 27

how carbohydrates aid in fat

Answer 27

-compounds in the TCA cycle are used in other biosynthetic pathways -depeletion of TCA components slows down the reations -TCA components are replaced by carbohydrates (and amino acids)

Question 28

ketone bodies

Answer 28

-often from a hormone imbalance (too little insulin-diabetes) -low carbohydrate diet -used by other tissue -fruity smell -blood can become acidic -fasting-decrease in insulin, increase in fat degradation

Question 29

protein metabolsim

Answer 29

-takes place in the liver except branch chain amino acids (muscle) -starts with removal of amino group (deamination or trans animation-requires vitamin B6) -glucogenic amino acids (alanine, glycine, cysteine, serine, asparagine, histidine, glutamine, isoleucine, methionine, proline, valine, phenylalanine, and threonine) -ketogenic amino acids (leucine, lysine, isoleucine, tryptophan, tyrosine and phenylalanine)

Question 30

urea cycle

Answer 30

-ammonia is toxic to the brain -urea cycle occurs in hepatic cells (liver) in Both the cytosol and mitochondria -NH3 + R-NH2 + CO2 -> Urea

Question 31

gluconeogenesis

Answer 31

-occurs in kidney and liver -starts in mitochondria with the formation of oxaloacetate -not possible from fatty acids

Question 32

regulation of energy metabolism

Answer 32

-ATP/ADP ratio -enzyme **expression level **activity -hormones **insulin, glucagon, etc. -vitamins and minerals

Question 33

postprandial fasting (0-6 hours after eating)

Answer 33

-use glycogen -fatty acids from adipose -break down lean tissue to utilize glycogenic amino acids to make glucose for the brain

Question 34

short term fasting (3-5 days)

Answer 34

-no carbohydrate left -lean muscle continues to be broken down-provides 90% of the glucose -10% of glucose comes from

Question 35

long term fasting (5+ days)

Answer 35

-no carbohydrate left -metabolsim slows -brain uses more ketone bodies -less glucose -death occurs when lean body mass decreases below 50%