Ch 12: Bioenergetics and Regulation of Metabolism

Question 1

Changes in ____ in a closed system are equal to changes in ____, which is equal to ____ heat exchange within the environment

Answer 1

enthalpy
internal energy
heat exchange

Question 2

no work is performed in a ____ system because ____ and ____ remain constat

Answer 2

closed

pressure and volume

Question 3

entropy

Answer 3

measure of energy dispersion in a system

Question 4

____ concentrations are usually much less than ____ concentrations

Answer 4

physiological

standard

Question 5

free energy concentrations must be adjusted for

Answer 5

pH (delta G knot ‘)
temperature (37 C = 310 K)
concentrations

Question 6

ATP

Answer 6

mid-level energy molecule

Question 7

ATP contains high-energy phosphate bonds that are stabilized upon hydrolysis by

Answer 7

resonance, ionization, and loss of charge repulsion

Question 8

ATP provides energy through ____ and ____ to energetically unfavorable reactions

Answer 8

hydrolysis and coupling

Question 9

ATP can also participate in ____ as a phosphate donor

Answer 9

phosphoryl group transfers

Question 10

May be soluble or membrane-bound

Answer 10

electron carriers

Question 11

Flavoproteins

Answer 11

one subclass of electron carriers that are derived from riboflavin (vit B2)

Question 12

Equilibrium is an undesirable state for most biochemical reactions because organisms need

Answer 12

to harness free energy to survive

Question 13

In the postprandial/well-fed (Absorptive) state,

Answer 13

insulin secretion is high and anabolic metabolism prevails

Question 14

In postabsorptive (fasting) state,

Answer 14

insulin secretion decreases while glucagon and catecholamine secretion increases

this is thee state observed in short-term fasting (overnight)

there is a transition to catabolic metabolism

Question 15

Prolonged fasting (starvation) dramatically

Answer 15

increases glucagon and catecholamine secretion

most tissues rely on fatty acids

at max, 2/3 of brain energy can be derived from ketone bodies

Question 16

Have opposing activities during most aspects of metabolism

Answer 16

insulin and glucagon

Question 17

Insulin causes

Answer 17

a decrease in blood glucose levels by increasing cellular uptake

Question 18

Insulin increases

Answer 18

the rate of anabolic metabolism

Question 19

Insulin secretion by pancreatic B cells is regulated by

Answer 19

blood glucose levels

Question 20

Glucagon increases blood glucose levels by

Answer 20

promoting gluconeogenesis and glycogenolysis in the liver

Question 21

Glucagon secretion by pancreatic alpha-cells is stimulated by both

Answer 21

low glucose and high protein levels

Question 22

Glucocorticoids

Answer 22

increase blood glucose in response to stress by mobilizing fat stores and inhibiting glucose uptake

increase the impact of glucagon and catecholamines

Question 23

Catecholamines

Answer 23

promote glycogenolysis and increase basal metabolic rate through their sympathetic nervous system activity

Question 24

Thyroid hormones

Answer 24

modulate the impact of other metabolic hormones and have a direct impact on basal metabolic rate (T3/T4)

Question 25

T3 is more ____ than T4

but has a shorter ____ and is available in ____ concentrations in the blood

Answer 25

potent
half-life
lower

Question 26

T4 is converted to T3 at

Answer 26

the tissues

Question 27

most metabolically diverse tissue

Answer 27

liver

Question 28

hepatocytes are responsible for

Answer 28

maintenance of blood glucose levels by glycogenolysis and gluconeogenesis in response to pancreatic hormone activity

Question 29

liver also participates in processing of

Answer 29

lipids and cholesterol, bile, urea, and toxins

Question 30

Adipose tissue store ____ under the influence of ____ and releases them under the influence of ____

Answer 30

lipids

insulin

epinephrine

Question 31

differs based on the current activity level and fiber type

Answer 31

skeletal muscle metabolism

Question 32

resting muscle conserves ___ in ____ stores and uses ____ from the ____

Answer 32

carbohydrates
glycogen
free fatty acids
bloodstream

Question 33

active muscle may use ___ (x4) depending on fiber type and exercise duration

Answer 33

anaerobic metabolism
oxidative phosphorylation
direct phosphorylation from creatine phosphate
fatty acid oxidation

Question 34

use fatty acid oxidation in both well-fed and fasting states

Answer 34

cardiac muscle

Question 35

brain and other nervous tissues consume glucose in

Answer 35

all fasting states, except prolonged fasts, where up to 2/3 of brain fuel comes from ketone bodies

Question 36

metabolic rates can be measured using

Answer 36

calorimetry, respirometry, consumption tracking, or measurement of blood concentraions of substrates and hormones

Question 37

respiratory quotient (RQ)

Answer 37

composition of fuel that is actively consumed by the body is estimated by this

Question 38

hormones leptin, ghrelin, and orexin play a role in

Answer 38

body mass

Question 39

long term changes in body mass arise from changes in

Answer 39

lipid storage

Question 40

changes in consumption or activity must

Answer 40

surpass a threshold to cause weight change.. it is lower for weight gain than weight loss