bioenergetics and exercise metabolism

Question 1

what is biogenetic?

Answer 1

• flow and change of energy within a living system, conversion of foodstuffs into usable energy for cell work

Question 1

what is the cell membrane

Answer 1

• semipermeable membrane separating cell from extracellular environment

Question 2

what is the nucleus

Answer 2

• contains genes regulating protein synthesis

Question 3

what is cytoplasm

Answer 3

• fluid containing organelles

Question 4

what is the mitochondria

Answer 4

• location of oxidative phosphorylation

Question 5

definition of metabolism

Answer 5

• sum of all chemical reaction occurring in the body -splits into anabolic and catabolic reactions

Question 6

what are anabolic reactions?

Answer 6

synthesis of molecules (glucose stored as glycogen)

Question 7

what are catabolic reactions?

Answer 7

breakdown of molecules (glycogen broken down to glucose)

Question 8

what is the 1st law of thermodynamics?

Answer 8

• energy cannot be created or destroyed but transformed from one form to another

Question 9

what are the 2 types of cellular chemical reactions?

Answer 9

1. endergonic = requires energy to be added to reactants 2. exergonic = releases energy

Question 10

describe oxidation-reduction reactions

Answer 10

• always coupled - oxidation = removing an electron - reduction = addition of an electron - NAD and FAD important role in transfer of H atoms with their electrons and act as carriers molecules in electron transport chain

Question 11

what are enzymes?

Answer 11

• proteins that lower energy of activation and accelerate chemical reactions - increase rate of production formation

Question 12

how to enzyme reactions work?

Answer 12

• substrate molecules bind to the active site of the enzyme molecule - create a product molecule unfaltering the enzyme molecule they binded to

Question 13

classify kinase

Answer 13

add a phosphate group

Question 14

classify dehydrogenases

Answer 14

remove hydrogen atoms

Question 15

classify oxidases

Answer 15

catalyse oxidation-reduction reactions involving oxygen

Question 16

classify isomerases

Answer 16

rearrangement of structure of molecules

Question 17

what changes to cellular environment influence enzyme activity

Answer 17

• temperature - pH

Question 18

describe ATP

Answer 18

• high energy phosphate molecule - synthesis is ADP+Pi > ATP - breakdown is ATP>ATPase»ADP+Pi+energy

Question 19

what are the 2 metabolic pathways used to form ATP

Answer 19

1. anaerobic - doesn’t involve O2, phosphocreatine breakdown and glycolysis 2. aerobic - require O2, oxidative phosphorylation and dependant on respiratory and cardiovascular systems to deliver O2

Question 20

step by step glycolysis

Answer 20

1. ATP breakdown activates energy flux through reactions of glycolytic pathway 2. produces ATP, 2NADH, 2 pyruvate or 2 lactate 3. net gain depends on substrate. glucose = 2 ATP and glycogen = 3 ATP 4. 2 phases - energy investment and energy generation 5. 30-90s

Question 21

step by step ATP-PC system

Answer 21

• most rapid and simplest method of ATP production through phosphocreatine breakdown - limited capacity so depletes after 10-15s

Question 22

what are electron carrier molecules

Answer 22

• for chemical reactions in glycolysis to continue, adequate amounts of NAD+ must be available to accept H+ - therefore NAD+ needs to be rapidly reformed from NADH by sufficient O2 shuttles to mitochondria for ATP generation (aerobic) but with O2 absence pyruvate can accept H to form lactate (anaerobic)

Question 23

what cycles are needed for aerobic ATP generation

Answer 23

1. citric acid cycle = completes oxidation of acetyl coA to provide electrons for the ETC 2. ETC = energy obtained from ET used to produce ATP at end of chain

Question 24

explain the citric acid cycle

Answer 24

1. glycolysis generates 2 pyruvate molecules 2. pyruvic acid (3-c) > mitochondria and is converted into acetyl coA (2-c) losing a carbon generating co2 3. acetyl coA binds with oxaloacetate (4-c) forming citrate (6-c) 4. these series of reactions regenerate oxaloacetate generating CO2s 5. each cycle = 1 ATP releasing electros 3 NADH snd 1 FADH2

Question 25

explain the electron transport chain

Answer 25

1. NADH and FAD are oxidised releasing electrons from H atoms 2. these then passed down electron carriers called cytochromes coupled with pumping of H+ into intermembrane space 3. increased concentration of H+ ions in inter membrane space 4. movement of H+ through ATP synthase produces ATP 5. end of chain, O2 accepts electrons passed along and combines H to from water

Question 26

what are the rate limiting enzymes in biochemical pathways

Answer 26

1. found early in metabolic pathway 2. activity regulated by modulators

Question 27

what is the difference with trained and untrained individuals

Answer 27

• endurance trained individuals have lower O2 deficit than untrained as they have a better developed aerobic bioenergetic capacity - have a greater regional blood flow to active muscle (more capillaries) and increased cellular adaptation and efficiency - increased mitochondrial vol in muscle fibres resulting in less lactate production at beginning of exercise

Question 28

what happens ro ATP production from rest to exercise

Answer 28

1. ATP production has immediate increase 2. oxygen uptake rapidly increases reaching steady state within 1-4 mins 3. initial ATP production through anaerobic pathways 4. creates oxygen deficit

Question 29

how do we recovery from exercise

Answer 29

• oxygen uptake still elevated above rest during recovery - O2 debt - elevation is a repayment for O2 deficit at onset of exercise - EPOC - this has replaced O2 debt and reflexes 20% elevated O2 consumption used to repay O2 deficit

Question 30

fast phase of EPOC

Answer 30

• resynthesis of stored PC in muscle and replenishing muscle and bloods O2 stores

Question 31

slow phase of EPOC

Answer 31

• elevate HR and BR increase O2 demand. increase body temp, blood elves, epinephrine and norepinephrine all increase metabolic rate - conversion of lactic acid to glucose

Question 32

what is carbs energy source, yield, stored from and where and the breakdown process

Answer 32

• source = glucose - yield = 4kcal/g -stored from = glycogen - where = liver and muscle - breakdown = glycogenolysis

Question 33

what is fats energy source, yield, stored from and where and the breakdown process

Answer 33

• source - fatty acids - yield = 9kcal/g - stored from = triglycerides - where = muscle and adipose tissue - breakdown = lipolysis

Question 34

what is proteins energy source, yield, stored from and where and the breakdown process

Answer 34

• source = amino acids - yield = 4kcal/g - storage and breakdown = contribute energy by glucogensis in liver and can be converted to metabolic intermediates