Bio Chapter 9-Cellular Respiration

cellular functions

cellular division

protein synthesis, produces enzymes and helps organism “save” energy

cellular use and production of energy ATP….

continual chemical process taking place

metabolism

sum of all chemical reactions taking place in the body

anabolism

requires enzymes

making/assembling large molecules

may require energy ATP

catabolism

requires enzymes

breakdown of molecules

may release energy

eat to provide the building blocks to make…

proteins, enzymes, padding/insulation, and energy/ATP

cellular respiration

ATP production involves 3-step process

3 steps of cellular respiration

glycolysis

citric acid cycle

electron transport system

glycolysis

occurs in cytoplasm

glucose enters cell and is immediately broken down

9 enzymatically controlled steps to yield

glycolysis yield

4 ATP

2 pyruvate molecules

2 high energy electrons

aerobic

when oxygen is available

anaerobic

no oxygen available

no pyruvate, lactic acid is produced instead

pyruvate

• Molecule produced during glycolysis

• Contains three carbon atoms

• Can be converted into acetyl-CoA

• Plays a key role in cellular respiration

• Can be further metabolized in the Krebs cycle

anaerobic metabolism

tissues adapted to make ATP without oxygen aka lactic acid pathway

RBC’s only use

skeletal muscle

normal daily occurrence, lactic acid pathway

too much=pain

ischemia

tissue death when no oxygen is present

cori cycle

lactic acid from glycolysis is delivered to the liver

lactic acid dehydrogenase/ LDH

converts lactic acid back into pyruvic acid

pyruvic acid…

converted back into glucose and can have a few things happen

what happens to pyruvic acid…

be converted into glycogen

be converted into free glucose and carried in blood to other cells to make ATP

go through glycolysis

glycogen

storage format of glucose, limited ability to store this

citric acid/ krebs cycle

2 pyruvate molecules enter the mitochondria (transition reaction) yields 2 NAHD molecules

acetyle Co-A

pyruvate becomes this during Krebs cycle and combines with oxaloacetate (already there) to form citric acid

step 1 of krebs cycle yields

step yields 2 NADH molecules

step 2 of krebs cycle

conversion of citric acid back into oxaloacetate

step 2 krebs cycle yield

yield 8 high energy electrons (6 NADH and 2 FADH)

2 ATP and carbon dioxide

NAHD will each yield 3 ATP , FADH only yields 2 ATP

overall net yield= 30 ATP

NADH

Electron carrier molecule produced during cellular respiration. It carries high-energy electrons to the electron transport chain, where they are used to generate ATP.

FADH

FADH is a coenzyme involved in cellular respiration. It carries high-energy electrons during the Krebs cycle and electron transport chain, aiding in ATP production.

electron transport system (cytochrome)

still in mitochondria but now inside the “folds”

high energy electrons NADH and FADH are used to produce ATP

final ATP yield from 1 molecule of glucose is

38 ATP

every step requires

its own enzyme

fat can produce….

2x as much ATP as glucose but has a higher cost

using fat for extended period to make ATP….

can lead to accumulation of ketones, harmful

ketosis

occurs in diabetics since they cannot use glucose so fat is the main fuel source