Chapter 24 Carbohydrate/ lipid/ protein metabolism

Question 1

where does digestion of carbohydrates happen? what enzyme? what are examples of the types digested?

Answer 1

mouth via salivary alpha-amylase
starch
glycogen
sucrose
lactose

Question 2

where does the digestion of polysaccharides happen? what enzyme?

Answer 2

stomach
& small intestine
- pancreatic alpha-amylase
- maltase
- sucrase
- lactase

Question 3

where do monosaccharides go once they are digested?

Answer 3

absorbed through small intestine lining & enter through bloodstream

Question 4

what protein allows for the entry of glucose into the host cell?

Answer 4

insulin

Question 5

once entered the cell, what occurs to allow for glucose to remain inside the cell to undergo glycolysis? how does this help keep it in the cell?

Answer 5

phosphorylation occurs
phosphate functional group is polar which keeps glucose from being able to cross the nonpolar inter-cell membrane space

Question 6

why every intermediate in glycolysis contains a phosphate

Answer 6

keeps it within the cell as it gets broken down

Question 7

what is the energy investment phase of glycolysis? what type of enzymes are used? ender/exergonic?

Answer 7

where ATP is converted to ADP
using transferase (spec. kinase) enzymes
endergonic reaction

Question 8

what is the energy generating phase of glycolysis? what type of enzymes are used? ender/exergonic?

Answer 8

where ADP is converted to ATP
oxidoreductase + transferase
exergonic

Question 9

how is it that more ATP is produced than consumed in glycolysis

Answer 9

the energy investment phase only occurs once using 2 ATP
its product is two molecules that then each produce 2 ATP leading to net 2 ATP

Question 10

why is pyruvate the end stage of glycolysis? why can’t more ATP be created?

Answer 10

it no longer has a phosphate functional group to keep it polar and remain inside the cell, so it is able to/will leave the cell

Question 11

what type of enzyme is used? ender/exergonic?

Answer 11

isomerase
neutral

Question 12

what type of enzyme is used? ender/exergonic?

Answer 12

transferase
endergonic

Question 13

what type of enzyme is used? ender/exergonic?

Answer 13

oxidoreductase & transferase
exergonic

Question 14

what type of enzyme is used? ender/exergonic?

Answer 14

transferase
exergonic

Question 15

what type of enzyme is used? ender/exergonic?

Answer 15

isomerase
neutral

Question 16

what type of enzyme is used? ender/exergonic? what type of reaction?

Answer 16

lyase
neutral
dehydration

Question 17

what type of enzyme is used? ender/exergonic?

Answer 17

transferase
exergonic

Question 18

what is the net result of glycolysis?

Answer 18

Question 19

what does the body do to other sugars such as fructose, galactose, and mannose?

Answer 19

uses other sugars to form the different reactants within glycolysis

Question 20

what happens to pyruvate after formed in glycolysis when there is oxygen present? what is the reaction called?

Answer 20

is used to form acetyl-CoA to be used in Kreb’s cycle
Pyruvate oxidation

Question 21

why is it that pyruvate can only be easily converted into acetyl-CoA when oxygen is present?

Answer 21

if oxygen is not plentiful, we will not be able to have NAD+ available for this reaction

Question 22

what is the net reactants/products of glycolysis?

Answer 22

Question 23

what is the net reactants/products of pyruvate oxidation?

Answer 23

Question 24

what is the net reactants/products of citric acid cycle?

Answer 24

Question 25

what is the total energy output of one glucose?

Answer 25

Question 26

what happens when there is not enough oxygen in the body to properly undergo Kreb's cycle? when does this occur?

Answer 26

to keep glycolysis going, the body regenerates NAD+ by reducing pyruvate to lactate occurs during exercise in which the body release lactase which causes soreness

Question 27

what is fermentation?

Answer 27

the production of energy under anaerobic conditions

Question 28

what is alcoholic fermentation?

Answer 28

the anaerobic breakdown of glucose to ethanol and CO2 by the action of yeast enzymes

Question 29

what type of enzyme? ender/exergonic?

Answer 29

oxidoreductase endergonic

Question 30

what is gluconeogenesis?

Answer 30

synthesis of glucose from noncarbohydrates such as lactate, amino acids, or glycerol (essentially glycolysis but in reverse)

Question 31

is gluconeogenesis ender/exergonic? is it anabolic or catabolic?

Answer 31

endergonic anabolic

Question 32

why is it that gluconeogenesis cannot be done completely in revese? what is the workaround?

Answer 32

the net delta G is overall endergonic if done in complete reverse, and this is unfavorable. 2 processes of exergonic are needed in order to perform the reaction (Co2 and ATP as reactants)

Question 33

fill in the blanks

Answer 33

Question 34

fill in blank. what type of enzyme? ender/exergonic?

Answer 34

ligase endergonic

Question 35

is the loss of CO2 ender/exergonic? what about the GTP to GDP?

Answer 35

both exergonic

Question 36

what is the definition of triglyceride mobilization?

Answer 36

hydrolysis of triacylglycerols in adipose tissue and release of fatty acids into the bloodstream

Question 37

when does mobilization of triglycerides occur?

Answer 37

when insulin is low and glucagon is high (glucose short supply)

Question 38

what happens to the glycerol that is hydrolyzed from triglycerides?

Answer 38

delivered to liver or kidneys and then converted into dihydroxyacetone phosphate to be entered into the 5th step of glycolysis or gluconeogenesis

Question 39

what is an oxidoreductase?

Answer 39

involves addition of O2 to a substrate reduction of a substrate or removal of two atoms to form a double bond

Question 40

what is a transferase?

Answer 40

transfer of amino groups between substrates transfer of a phosphoryl group between substrates

Question 41

what is a hydrolase?

Answer 41

using water to break down a substrate into 2 new molecules

Question 42

what is an isomerase?

Answer 42

isomerization of a substrate

Question 43

what is a lyase?

Answer 43

removal of H2O from substrate to give double bond replacement of a carboxyl group by a hydrogen addition of small molecule to a double bond

Question 44

what is a ligase?

Answer 44

using two substrates to create 1 new product

Question 45

what are examples of oxidoreductases?

Answer 45

oxidase reductase dehydrogenase

Question 46

what are examples of tranferases?

Answer 46

transaminases kinase

Question 47

what are examples of hydrolases?

Answer 47

lipase protease nuclease

Question 48

what are examples of lyases?

Answer 48

dehydrase decarboxylase synthase

Question 49

what are examples of ligases?

Answer 49

synthetases carboxylases

Question 50

what type of enzyme? what type of reaction? ender/exergonic?

Answer 50

Question 51

what type of enzyme? what type of reaction? ender/exergonic?

Answer 51

Question 52

what type of enzyme? what type of reaction? ender/exergonic?

Answer 52

Question 53

what type of enzyme? what type of reaction? ender/exergonic?

Answer 53

Question 54

what type of enzyme? what type of reaction? ender/exergonic?

Answer 54

Question 55

what type of enzyme? what type of reaction? ender/exergonic?

Answer 55

Question 56

what type of enzyme? what type of reaction? ender/exergonic?

Answer 56

oxidoreductase dehydrogenation exergonic

Question 57

what type of enzyme? what type of reaction? ender/exergonic?

Answer 57

lyase hydration neutral

Question 58

show what would happen if a kinase was introduced?

Answer 58

Question 59

what is beta oxidation?

Answer 59

4 step process that turns an 18 carbon fatty acids to produce 9 Co-A within 8 cycles

Question 60

what type of enzyme? what type of reaction? ender/exergonic?

Answer 60

oxidoreductase dehydrogenation exergonic

Question 61

what would be the outcome if this was a hydration reaction? what enzyme?

Answer 61

lyase

Question 62

what type of enzyme? what type of reaction? ender/exergonic?

Answer 62

oxidoreductase oxidation exergonic

Question 63

what would be the product? what enzyme?

Answer 63

transferase

Question 64

how many cycles will an 18 carbon go through beta oxidation? how many products will it produce?

Answer 64

8 cycles 9 acetyl-CoA

Question 65

what type of cycle is beta oxidation? linear, spiral, or cyclic?

Answer 65

spiral

Question 66

can the body gain more energy by using fats or sugar?

Answer 66

fats gain 2.3 times more energy per gram of fat than per gram of glucose

Question 67

what is lipogenesis?

Answer 67

pathway for making of fatty acids from acetyl-CoA

Question 68

is lipogenesis the exact reaction of beta oxidase in reverse?

Answer 68

not the exact reverse reaction

Question 69

where does beta oxidation occur? where does lipogenesis occur?

Answer 69

beta: in mitochondria lipo: in cytosol

Question 70

when you buy carboxylic acids with odd number of carbons, why is it more expensive?

Answer 70

in nature, carboxylic acids are mostly found with even number of carbons. even lipogenesis and beta oxidation produces lipids with even number of carbons

Question 71

Triacylglycerol synthesis starts with what reactants?

Answer 71

with glycerol 3-phosphate + fatty acids

Question 72

Answer 72

Question 73

Answer 73

Question 74

what is transamination?

Answer 74

use of existing amino acids to make new ones

Question 75

what is oxidative deamination?

Answer 75

removal of amino group to produce an alpha keto group

Question 76

Answer 76

Question 77

what are the essential amino acids? how many are there?

Answer 77

amino acids that cannot be synthesized in the body, and are needed from diet 9

Question 78

how many nonessential amino acids?

Answer 78

11

Question 79

All nonessential amino acids derive their amino groups from what amino acid? how is glutamate formed?

Answer 79

glutamate from reductive amination of ketoglutarate

Question 80

what is the process of creating other amino acids from glutamate?

Answer 80

transamination

Question 81

what is reductive amination?

Answer 81

conversion of keto acids to amino acids by reactions with NH4+

Question 82

what is the normal blood glucose range?

Answer 82

65-100 mg/dL

Question 83

what is hypoglycemia? what are symptoms?

Answer 83

lower than normal blood glucose concentration weakness, sweating, rapid heartrate

Question 84

what is hyperglycemia? symptoms?

Answer 84

higher than normal blood glucose concentrations increased urine flow

Question 85

what is the function of insulin? when is it found circulating?

Answer 85

- used to tell cells to accept glucose into the cell found when blood glucose is high

Question 86

what is the function of glucagon? when is it found circulating?

Answer 86

- keeps existing glucose out of cells/ break down glycogen + find other ways to make glucose (glucose sparing) found when blood glucose is low

Question 87

what hormone speeds up glycogen breakdown only in the muscles?

Answer 87

epinephrine

Question 88

how long can the body use glycogen reserves?

Answer 88

15-20 hours

Question 89

what does the brain use when glycogen supply is depleted?

Answer 89

proteins

Question 90

how many grams of protein are used per day to metabolize glucose for the brain?

Answer 90

75 grams of protein per day

Question 91

when glycogen supply is depleted, what does the rest of the body use to get its energy supply replenished? what is wrong with this process? what is the workaround?

Answer 91

beta oxidation begins to convert lipids into acetyl-CoA to be used in citric acid cycle to then make ATP citric acid cycle cannot keep up with the demands of being the only one to make ATP ketogenesis is the work around

Question 92

what are the reactants and products of ketogenesis?

Answer 92

reactants: 2 acetyl-CoA product: ketone bodies such as 3-Hydroxybutyrate, acetoacetate, and acetone

Question 93

how much ATP does ketogenesis make compared to citric acid cycle?

Answer 93

keto: 1.25 ATP per acetyl-CoA TCA: 10 ATP per acetyl-CoA

Question 94

would ketogenesis be considered energy-effecient?

Answer 94

no, it is very inefficient; it's used as a last ditch effort to provide ATP when the body believes it is starving

Question 95

how many kcal in 1 gram of protein? how many kcal in 1 gram of fat?

Answer 95

protein: 4 kcal fat: 9 kcal

Question 96

how many kcals does ketogenesis make?

Answer 96

uses 25 g of protein = 25 x 4 = 100 kcal uses 180 g of fat = 180 x 9 = 1620 kcal

Question 97

what is the purpose of the keto diet?

Answer 97

restrict carbohydrate consumption to make your body believe it is starving for carbs so that it switches to burning fat as its main energy source

Question 98

what is diabetes mellitus?

Answer 98

chronic condition due to either insufficient insulin or failure of insulin to promote glucose uptake in cells

Question 99

what is type 1 diabetes?

Answer 99

autoimmune disease - attacks pancreatic cells. fewer pancreatic cells cause there to be less insulin production this causes glucose to build up in the blood

Question 100

what is type II diabetes?

Answer 100

there is plenty of insulin, but the cells receptors for insulin become tolerant of insulin, so insulin cannot perform its job correctly and cell does not uptake glucose

Question 101

what two conditions cause citric acid cycle to become overwhelmed? what is a likely outcome of this?

Answer 101

starvation & diabetes ketogenesis

Question 102

one of the ketone bodies has a ketone functional group, but the other two do not. what functional group do they have?

Answer 102

carboxylic acids

Question 103

what is ketoacidosis?

Answer 103

lowered blood pH due to accumulation of the ketone bodies (spec. the carboxylic acids)

Question 104

who is most likely to be affected by ketoacidosis?

Answer 104

prolonged keto dieters diabetics starving people

Question 105

glutamine is formed from what amino acid?

Answer 105

glutamate

Question 106

asparagine is formed from what amino acid?

Answer 106

aspartate

Question 107

tyrosine is formed from what amino acid?

Answer 107

phenylalanine

Question 108

ketone bodies eventually break down, what do they produce?

Answer 108

CO2 and acetone