chap 9 muscular system III Flashcards Preview

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Flashcards in chap 9 muscular system III Deck (21):
1

motor unit

single motor neuron and all of muscle fibers it innervates

2

ATP

energy for muscle contraction comes from ATP
only small amounts are stored so new ATP must be continually synthesized

3

3 sources of new ATP within muscle fiber

creatine phosphate
anaerobic respiration
aerobic respiration

4

creatine phosphate (CP)

ATP can be sythesized when ADP reacts with creatine phosphate to form creatine and ATP
ADP+CP -> creatine + ATP

5

how long is ATP from creatine phosphate able to last

as long as the level of creatine phosphate is available in the cell
short time during intense exercise

6

how many seconds of sustained activity can CP synthesized ATP last?

8-15 seconds of sustained muscle activity

7

anaerobic respiration

if enery demands exceed oxygen supply to the cell, ATP is synthesized by anaerobic respiration and is used to provide energy for a short time during intense excercise

8

anaerobic respiration is... compared to aerobic

more rapid, but less efficient

9

where does anaerobic respiration occur

in the cytoplasm and begins with glycolysis

10

glycolysis

glucose (six carbon sugar) is split into 2 three carbon compounds called pyruvate

11

what happens to pyruvate after created?

goes through lactic acid fermentation to yield a net of 2 ATP molecules per glucose molecule

12

anaerobic respiration formula

C6H12O6 (glucose) --> pyruvate --> 2 lactic acid + 2 ATP + heat

13

what happens to waste products

lactic acid molecules diffuse out of the cell to blood plasma
liver cells convert

14

what do liver cells convert?

lactic acid + O2 --> eventual glucose molecule

15

aerobic respiration

used during resting conditions or during excercises such as long distance running
also begins with glycolysis in the cytoplasm

16

aerobic respiration is... compared to anaerobic respiration

more efficient but slower

17

what happens to the pyruvate during aerobic respiration

pyruvate are sent into the mitochondria where they go through the citric acid cycle (krebs cycle) and electron transport chain

18

how much ATP is created through aerobic respiration?

36-38 ATP molecules per glucose molecule

19

aerobic respiration formula

C6H12O6 (glucose) --> pyruvate +O2 --> CO2 + H20 + 38 ATP + heat

20

dealing with waste formula

CO2+H20 H2CO3 (carbonic acid) H+ + HCO3

21

oxygen debt

the amount of O2 needed (above that required for resting metabolism) to recover after vigorous exercise
myoglobin will attach to oxygen
for conversion of lactic acid to glucose in liver
for resting cells to replenish their ATP and CP synthesis