excercise physiology exam 1 chapters 1-4 Flashcards Preview

ap2 endocrine, blood, heart, ig tract, genetics, nutrition > excercise physiology exam 1 chapters 1-4 > Flashcards

Flashcards in excercise physiology exam 1 chapters 1-4 Deck (56)
Loading flashcards...
1
Q

A.V. Hill – nobel prize

A

Heat production during muscle contraction and recovery

2
Q

Otto Meyerhof –nobel prize

A

Relationship of O2 consumption and lactic acid in muscle

3
Q

–August Krogh-nobel prize

A

Function of the capillary circulation

4
Q

D.B. Dill

A

–Directed the Harvard fatigue lab from 1927–1947; D.B Dill Conducted research in numerous areas such as Exercise, clinical, and environmental physiology. Basis of much of what we know today. He was able to make precise measurements with” new” instruments and techniques. Active Research Areas in the Harvard Fatigue Laboratory
–Aging –Blood–Physical fitness –Metabolism–Environmental physiology –Clinical physiology

5
Q

Homeostasis

A

Maintenance of a constant and “normal” internal environment

6
Q

Steady state

A

–Physiological variable is unchanging, but not necessarily “normal it is the Balance between demands placed on body and the body’s response to those demands

7
Q

Oxidation

A

Removing an electron

8
Q

Reduction

A

Addition of an electron

9
Q

Endergonic reactions

A

Require energy to be added to the reactant

10
Q

Enzymes

A

Catalysts that regulate the speed of reactions

Lower the energy of activation but do not alter nature of reaction

11
Q

Factors that regulate enzyme activity

A

Temperature, ph

12
Q

Exergonic reactions

A

Release energy

13
Q

Coupled reactions

A

Release of energy in an exergonic reaction drives an endergonic reaction

14
Q

Metabolism

A

Sum of all chemical reactions that occur in the body Anabolic reactions Synthesis of molecules Catabolic reactions
Breakdown of molecules

15
Q

Bioenergetics

A

Converting foodstuffs (fats, proteins, carbohydrates) into energy

16
Q

Cell membrane

A

Semipermeable membrane that separates the cell from the extracellular environment

17
Q

Nucleus

A

Contains genes that regulate protein synthesis

Molecular biology

18
Q

Cytoplasm

A

(called sarcoplasm in muscle). Fluid portion of cell
Contains organelles
Mitochondria

19
Q

Negative Feedback

A

Response reverses the initial disturbance in homeostasis

20
Q

example of negative feedback

A

Increase in extracellular CO2 triggers a receptor which Sends information to respiratory control center. Respiratory muscles are activated to increase breathing now CO2 concentration returns to normal

21
Q

Coenzyme functions

A

(1) Substrate such as pyruvate, need enzymes to be converted to other substrate.
(2) Before enzyme attaches to vitamin coenzyme, enzyme is in a closed position. After attachment, it is in opening position.

(3) The open, activated enzyme accepts the substrate.
(4) Split the substrate into two compounds while releasing the enzyme and vitamin coenzyme.

22
Q

Some factors that affect enzyme function are

A

Temperature–Small rise in body temperature increases enzyme activity–Exercise results in increased body temperature-pH–Changes in pH reduces enzyme activity–Lactic acid produced during exercise

23
Q

Carbohydrates

A

Blood sugar Glycogen Storage form of glucose in liver and muscle
Synthesized by enzyme glycogen synthase Glycogenolysis Breakdown of glycogen to glucose

24
Q

Fats:

A

Fatty acids
Triglycerides → glycerol and fatty acids
Storage form of fat in muscle and adipose tissue. Breaks down into glycerol and fatty acids Phospholipids
Not used as an energy source
Provide the structural integrity of cell membrane Provide the insulation of sheath around nerve fibers

25
Q

Steroids

A

The most common steroid is cholesterol

–Needed to synthesize sex hormones

26
Q

Steroid hormones-

A

are lipid soluble, most are formed from cholesterol.

27
Q

Non-steroid hormones -

A

are formed from proteins and amino acid.

28
Q

Protein

A

Composed of amino acids nine amino acids are essential and cannot be made by our body. Some can be converted to glucose in the liver also known as Gluconeogenesis. Others can be converted to metabolic intermediates (e.g some enzymes)
Contribute as a fuel in muscle in the bioenergetics pathways.

29
Q

Steps in protein synthesis

A
  1. DNA contains information to produce proteins.
  2. Transcription produces mRNA.
  3. mRNA leaves nucleus and binds to ribosome.
  4. Amino acids are carried to the ribosome by tRNA.
  5. In translation, mRNA is used to determine the arrangement of amino acids in the polypeptide chain(protein synthesis).
30
Q

Does Creatine Supplementation Improve Exercise Performance?

A

Depletion of PC may limit short-term, high-intensity exercise
Creatine monohydrate supplementation
Increased muscle PC stores
Some studies show improved performance in short-term, high-intensity exercise
Inconsistent results may be due to water retention and weight gain
Increased strength and fat-free mass with resistance training
Creatine supplementation for 8 weeks does not appear to pose health risks

31
Q

Fast glycolysis

A

energy derived from the breakdown of glucose (or glycogen) to 2 (or 3) molecules of ATP and 2 molecules of lactic acid

32
Q

Lactic Acid – Implications for Performance

A

Lactic acid alters the pH of the cell

The higher acidity of the cell as a result of lactic acid production alters enzymatic activity (reactions occur at a slower rate)

The more lactic acid an athlete can produce, the greater power output the athlete can generate

A speed athlete must produce and tolerate great amounts of lactic acid to be successful

Lactic acid does not cause muscle soreness

33
Q

Lactic Acid or Lactate?

A

Terms lactic acid and lactate used interchangeably
Lactate is the conjugate base of lactic acid
Lactic acid is produced in glycolysis
Rapidly disassociates to lactate and H+

The ionization of lactic acid forms the conjugate base called lactate

34
Q

Non-oxidative System (Fast glycolysis)

A

Non-oxidative energy sources in muscle are the breakdown of glucose (simple sugar) and glycogen (stored in liver).

The breakdown of glucose: Glycolysis
The breakdown of glycogen: Glycogenolysis
3. In skeletal muscle, the concentration of free glucose is very low so the
most of potential energy available from non-oxidative energy sources
comes from the breakdown of glycogen .

  1. Non-Oxidative system offers about 15 Kcal/mole energy for total
    muscle mass that is greater than immediate energy system
    (11.1 Kcal/mole)
35
Q

Aerobic Metabolism

A

Aerobic ATP production occurs inside the mitochondria and involves the interaction of 2 cooperating metabolic pathways.

36
Q

Aerobic Metabolism: krebs cycle

A

Primary function is to complete the oxidation (H+ removal) of CHO, Fats or proteins using NAD & FAD as hydrogen (energy) carriers.
H+ molecules (their electrons) contain the potential energy in food molecules.This energy (H+ molecule) can be used in ETC (Electron Transport Chain) to combine:
ADP + Pi ATP.

37
Q

Aerobic Metabolism: Electron TRansport chain

A

Electron transport chain results in pumping of H+ ions across inner mitochondrial membrane (from inner compartment to outer compartment)
Results in H+ gradient across membrane
Energy released to form ATP as H+ diffuse back across the inner membrane (from outer compartment to inner compartment)

38
Q

Aerobic ATP Production

A

Electron transport chain
Oxidative phosphorylation occurs in the mitochondria
Electrons removed from NADH and FADH are passed along a series of carriers (cytochromes) to produce ATP
Each NADH produces 2.5 ATP
Each FADH produces 1.5 ATP
H+ from NADH and FADH are accepted by O2 to form water

39
Q

Efficiency of Oxidative Phosphorylation

A

Aerobic metabolism of one molecule of glucose
Yields 32 ATP
Aerobic metabolism of one molecule of glycogen
Yields 33 ATP
Overall efficiency of aerobic respiration is 34%
66% of energy released as heat

40
Q

Amino Acid Metabolism

A

Protein primarily utilized to build and repair tissue

Contributes only small percentage of total energy production

2-3% of total energy at rest
12-15% of total energy at maximal, exhaustive exercise

41
Q

Rate-limiting enzymes

A

An enzyme that regulates the rate of a metabolic pathway

42
Q

Modulators of rate-limiting enzymes

A

Levels of ATP and ADP+Pi
High levels of ATP inhibit ATP production
Low levels of ATP and high levels of ADP+Pi stimulate ATP production
Calcium may stimulate aerobic ATP production

43
Q

Interaction Between Aerobic/Anaerobic ATP Production

A

Energy to perform exercise comes from an interaction between aerobic and anaerobic pathways
Effect of duration and intensity
Short-term, high-intensity activities
Greater contribution of anaerobic energy systems
Long-term, low to moderate-intensity exercise
Majority of ATP produced from aerobic sources

44
Q

VO2

A

Ability to Deliver & Use Oxygen

45
Q

Absolute VO2

A

Liters per minute (L/min)

46
Q

Relative VO2

A

ml per kg of body weight per minute (ml/kg/min)

47
Q

Energy Requirements at Rest

A

Almost 100% of ATP produced by aerobic metabolism

Blood lactate levels are low (<1.0 mmol/L)

Resting O2 consumption (70 kg adult):

  1. 25 L/min (absolute VO2)
  2. 5 ml/kg/min (relative VO2)
48
Q

MET

A

The expression of energy cost for activities in a simple unit.

49
Q

Oxygen Deficit:

A

the difference between the total oxygen actually consumed during exercise and the total oxygen required (consumed) in steady-rate from the start of exercise.

50
Q

Summary for O2 Deficit

A

As begin exercise, not producing enough O2 to do work:

(1) Accumulate Lactate			
(2) This is the O2 deficit			
(3) This will have to be paid back (metabolized later
51
Q

Excess Postexercise Oxygen Consumption (EPOC)

A

After exercise, O2 consumption does not return to resting levels immediately.

Then, the extra O2 consumed during recovery, above a resting baseline is called Excess Postexercise Oxygen Consumption (EPOC). EPOC is also termed O2 debt. Oxygen consumption remains elevated following exercise Classical term – oxygen debt Depends on intensity and duration of activity Rapid curve component (“Rapid” portion ) – steep decline
Slow curve component (“Slow” portion)

52
Q

Metabolic Responses to Prolonged Exercise

A

Prolonged exercise (>10 minutes)
ATP production primarily from aerobic metabolism
Steady-state oxygen uptake can generally be maintained during submaximal exercise
Prolonged exercise in a hot/humid environment or at high intensity
Upward drift in oxygen uptake over time
Due to body temperature and rising epinephrine and norepinephrine

53
Q

Lactate Threshold

A

The point at which blood lactic acid rises systematically during incremental exercise
Appears at ~50–60% VO2 max in untrained subjects
At higher work rates (65–80% VO2 max) in trained subjects

54
Q

Factors affecting lactate appearance and disappearance

A
[La] = rate of appearance – rate of disappearance
What affects appearance?
Production and release
Recruitment of fast twitch fibers
LDH isoform
Increased epinephrine
What affects disappearance?
Rate of uptake into non-working muscles
Oxidation by muscles, liver
Blood flow
55
Q

Removal of Lactate

A

70% - oxidized by other tissues

20% - converted to glycogen or glucose in liver (Cori Cycle)

10% - converted to amino acids

56
Q

RER (respiratory exchange ratio)

A

RER-respiratory exchange ratio