Quiz 1

Question 1

Structural Breakdown of Muscle

Answer 1

muscle is made of fasculi, which are made of myofibers (muscle cells), which are made of myofibrils (sub-cellular contractile units)

Question 2

Components of a myofiber

Answer 2

Sarcoplasmic reticulum, transverse tubules, plasmalemma, terminal cistern,actin and myosin fibers; many mitochondria

Question 3

Sarcomere

Answer 3

Z-disk to Z-disk; composed of myosin and actin; shortens until the light band almost disappears during contraction

Question 4

Myofibril

Answer 4

Structural and functional unit of the skeletal muscle system; either actin or myosin

Question 5

Isotropic Bands

Answer 5

light bands; basically where the actin strands are

Question 6

Anisotropic Bands

Answer 6

dark bands; basically where the myosin strands are

Question 7

Ratio of myosin to actin

Answer 7

1 myosin for every 6 actin;

Question 8

Connective Tissue in Muscle

Answer 8

endomysium (wraps every myofiber), perimysium (wraps every fascicle), and epimysium (wraps every muscle); gives toughness to transmit force that muscle tissue produces

Question 9

Myoneural Junction

Answer 9

where nerve meets muscle fiber; creates a motor unit

Question 10

Nerve Supply to Muscle

Answer 10

nerve/NT gets into sarcolemma and causes a wave of depolarization; T-tubules allow for nervous system to get down into the muscle cell quickly

Question 11

First Half of Muscle Cell Depolarization

Answer 11

alpha motor neuron sends nerve signal which is carried across mho-neural junction via acetylcholine; causes depolarization in the sarcolemma, which reaches deep into the muscle via T-Tubules; causes calcium to be released from sarcoplasmic reticulum

Question 12

Second Half of Muscle Contraction

Answer 12

calcium hooks up with troponin, causing a conformational change in tropomyosin, which normally covers actin’s binding site for myosin

Question 13

Tropomyosin

Answer 13

normally covers actin’s binding site for myosin, so prohibits contraction until an action potential is spread

Question 14

Troponin

Answer 14

causes a conformational change in tropomyosin so actin and myosin can bind; only is activated when calcium is released

Question 15

ATP’s Action in Muscle Contraction

Answer 15

on the myosin head ATP exists along with myosin ATPase, which allows for ATP to be broken down quickly which is needed in order for actin and myosin to bind and to unbind

Question 16

Sliding Filament Theory

Answer 16

rest, excitation-coupling, contraction, recharging, relaxation

Question 17

Phospho-Creatine System

Answer 17

the first source of ATP; creatine kinase breaks down phosphocreatine to release energy and phosphate, which is then used to rebuild ATP; anaerobic; 3-15sec;

Question 18

Glycolytic System

Answer 18

requires 2 ATP, creates 4 ATP; net gain of 2; produces pyruvic acid and lactic acid which prevents more time being spent using this system; also produces 2 NADH;

Question 19

Oxidative System

Answer 19

pyruvic acid, instead of becoming lactic acid, loses a CO2 and enters the mitochondria as acetyl coA; consists of the Krebs cycle and the ETC; 32 ATP total

Question 20

Rule for which system is used

Answer 20

intensity dictates duration

Question 21

Krebs cycle

Answer 21

the main purpose is to package and transport H+ for the ETC; only produces 2 ATP (one for each acetyl coA) and 10 NADH and 2 FADH;

Question 22

Electron Transport System

Answer 22

oxygen accepts H+ at the end of the ETC to produce water; FADH and NADH bring H+ to be accepted in the ETC; the splitting apart of FADH and NADH creates enough energy to put ATP back together again; 2.5 ATP for every NAD and 1.5 ATP for every FAD

Question 23

Aerobic Lipolysis

Answer 23

triglycerides broken down to allow free fatty acids to be released into the blood and then enters the mitochondria;

Question 24

ß Oxidation

Answer 24

takes the FFA and chops it into 2 carbon pieces and sends them to the Krebs cycle; with each cycle one NAD and FAD pick up H+ as well;

Question 25

ATP Calculation for ß Oxidation

Answer 25

for every chop (C-1) multiply by 4 ATP; for every acetyl choline multiply by 10 ATP (C); add these together and subtract 2 for this is the requirement to begin oxidation