Physiology 4

Front 1

what is metabolism?

Back 1

synthesis and breakdown of organic molecules required for cell structure and function and the release of chemical energy used for cell functions

Front 2

what is anabolism?

Back 2

the synthesis of organic molecules by cells

Front 3

what is catabolism?

Back 3

the breakdown of organic molecules by cells

Front 4

what is one calorie?

Back 4

the amount of heat energy required to raise the temperature of 1g of water 1 degree Celsius

Front 5

what four factors influence reaction rate?

Back 5

1) reactant concentration
2) activation energy
3) temperature
4) presence of a catalyst

Front 6

the lower the concentration of reactants the ____ the reaction

Back 6

slower

Front 7

the higher the concentration of reactants the ___ the reaction

Back 7

faster

Front 8

what is activation energy?

Back 8

energy required to overcome the mutual repulsion of the electrons surrounding the atoms in each molecule

Front 9

the higher the activation energy the ___ the reaction

Back 9

slower

Front 10

the lower the activation energy the ___ the reaction

Back 10

faster

Front 11

the higher the temperature the __ the reaction

Back 11

faster

Front 12

the lower the temperature the ___ the reaction

Back 12

slower

Front 13

describe chemical equilibrium

Back 13

forward and reverse reaction rates are equal

Front 14

describe irreversible reactions

Back 14

most of the reactant molecules are converted to product molecules when equilibrium is reached

Front 15

what determines the ratio of product concentration to reactant concentration at equilibrium?

Back 15

the amount of energy released or added

Front 16

what is the law of mass action?

Back 16

increase in reactant concentration causes a chemical reaction to proceed in direction of product formation

Front 17

what is an enzyme?

Back 17

a protein catalyst that accelerates specific chemical reactions but does not itself undergo net chemical change during the reaction

Front 18

describe the reaction between enzyme and substrate

Back 18

enzyme binds to substrate to form enzyme substrate complex which breaks down to form product and enzyme

Front 19

what is an enzyme's active site?

Back 19

the area of an enzyme that the substrate binds to

Front 20

what are the two models to describe enzyme substrate interaction

Back 20

1) lock and key model
2) induced fit model

Front 21

what are cofactors?

Back 21

required in small amounts to activate many enzymes

Front 22

how is a coenzyme different than a cofactor?

Back 22

a coenzyme is when the cofactor is an organic molecule that directly participates as one of the substrates in the reaction

Front 23

coenzymes are derived from several members of a special class of nutrients known as _____

Back 23

vitamins

Front 24

what are NAD and FAD derived from? and what do they play a role in

Back 24

b vitamins
play major roles in energy metabolism by transferring hydrogen from one substrate to another

Front 25

when is the maximal rate reached?

Back 25

when the enzyme becomes saturated with substrate and there are no more active binding sites

Front 26

how can a change in enzyme activity occur?

Back 26

allosteric change or covlent modulation alters properties of enzymes active site

Front 27

increasing an enzymes affinity does not increase the ____

Back 27

maximal rate

Front 28

what mediates covalent modulation of enzyme activity?

Back 28

protein kinase enzymes

Front 29

what two factors affect the rate of enzyme mediated reactions?

Back 29

enzyme concentration (enzyme synthesis or breakdown) and enzyme activity (allosteric modulation or covalent modulation)

Front 30

what is a metabolic pathway?

Back 30

a sequence of enzyme mediated reactions leading to the formation of a particular product

Front 31

what is end product inhibition?

Back 31

inhibition of a metabolic pathway b final product's action upon allosteric site on an enzyme in pathway

Front 32

how can an irreversible step be reversed?

Back 32

using a second enzyme and its substrate to provide the large amount of required energy

Front 33

the energy released during a chemical reaction is either ___ or ___

Back 33

released as heat or transferred to other molecules

Front 34

what are the three metabolic pathways to transfer the energy released from the breakdown of nutrient molecules to ATP?

Back 34

1) glycolysis
2) the Krebs Cycle
3) Oxidative phosphorylation

Front 35

glycolysis operates only on ____

Back 35

carbohydrates

Front 36

what are the categories of nutrients?
how do they contribute to ATP production

Back 36

carbohydrates, fats, and proteins
through the krebs cycle and oxidative phosphorylation

Front 37

what is the cite of the krebs cycle?

Back 37

mitochondria

Front 38

what is the cite of oxidative phosphorylation?

Back 38

mitochondria

Front 39

which require oxygen?
1) glycolysis
2) krebs cycle
3) oxidative phosphorylation

Back 39

1) glycolysis NO
2) krebs cycle YES
3) oxidative phosphorylation YES

Front 40

what is glycolysis?

Back 40

the pathway that partially catabolizes carbohydrates, primarily glucose

Front 41

how many enzymic reactions are involved in glycolysis?

Back 41

ten

Front 42

what is converted in glycolysis?

Back 42

a six carbon molecule of glucose is converted into two three carbon molecules of pyruvate

Front 43

what is the net synthesis of glycolysis?

Back 43

two molecules of ATP

Front 44

where does glycolysis occur?

Back 44

cytosol

Front 45

what are the two different directions that pyruvate can proceed in after glycolysis?

Back 45

1) in aerobic conditions it can enter the krebs cycle and be broken down into carbon dioxide
2) in anaerobic conditions, pyruvate is converted to lactate by a single enzyme mediated reaction

Front 46

in anaerobic conditions, what is pyruvate converted into? how?

Back 46

two hydrogen atoms derived from NADH+ + H+ are transferred to each molecule to form lactate

Front 47

what is the net reaction of glycolysis in aerobic conditions?

Back 47

Glucose + 2ADP + 2Pi + 2NAD+ >>>> 2 pyruvate + 2ATP + 2NADH + 2H+ + 2H2O

Front 48

what is the net reaction of glycolysis in anaerobic conditions?

Back 48

Glucose + 2ADP + 2Pi >>>>> 2lactate + 2ATP + 2H2O

Front 49

what cells only use glycolysis?

Back 49

erythrocytes

Front 50

what happens to lactate formed during glycolysis?

Back 50

-some is released into blood where it is taken up by tissues and converted back to pyruvate and used as energy source
-also taken up by liver where it is used as precursor for glucose formation

Front 51

where does krebs cycle occur?

Back 51

in matrix of mitochondria

Front 52

what is the primary molecule entering the krebs cycle?

Back 52

acetyl CoA

Front 53

why can krebs cycle only operate under anaerobic conditions?

Back 53

because oxidative phosphorylation is necessary for regeneration of the hydrogen free forms of coenzymes

Front 54

why is krebs cycle so important if it only directly produces one ATP molecule?

Back 54

because the hydrogen atoms transferred to coenzymes during cycle are used in oxidative phosphorylation to form large amounts of ATP

Front 55

what is the net reaction for krebs cycle?

Back 55

Acetyl CoA + 3 NAD+ + FAD + GDP + Pi + 2H2O >>>> 2CO2 + CoA + 3NADH+ 3H+ +FADH2 + GTP

Front 56

how is the energy transferred to ATP derived in oxidative phosphorylation?

Back 56

it is derived from the energy released when hydrogen ions combine with molecular oxygen to form water

Front 57

where does the hydrogen in oxidative phosphorylation come from?

Back 57

NADH and H+ and FADH2 (from krebs cycle)

Front 58

what is the net reaction for oxidative phosphorylation?

Back 58

1/2 O2 + NADH + H+ + 3ADP + 3 Pi >>>>>> H20 + NAD+ + 3ATP