Physiology Ch.3 Part 2 Energy

ATP

• “Adenosine triphosphate”

• Serves as the primary energy source for cells in the body

• Endergonic reaction done by synthesize by adding inorganic phosphate (P) to adenosine diphosphate (ADP)

Substrate-level phosphorylation

• Form of synthesizing ATP

• Phosphate group is transferred from metabolic intermediary to ADP molecule

• X-P + ADP = X + ATP

Oxidative phosphorylation

• Form of synthesizing ATP

• Free inorganic phosphate group is transferred to ADP molecule

• Only possible with electron transport system of mitochondria and O

• P + ADP = ATP

ATP Breakdown

• Process called ATP hydrolysis

• Necessary to remove energy from ATP to perforce endergonic reactions

• ATP (+H2O) = ADP + P + energy

Glucose Oxidation

• Multi-stage exergonic reaction that powers ATP synthesis in cells

- Stage 1: Glycolysis

- Stage 2: The Citric acid cycle / Krebs cycle / tricarboxylic acid (“TCA”) cycle

- Stage 3: Oxidative phosphorylation

• C6H12O6 + 6O = 6CO2 + 6H2O + energy

NAD

• Coenzyme

• Derived from niacin (vitamin B3)

• Caries electrons

FAD

• Coenzyme

• Derived from ribboflavin (vitamin B2)

• Caries electrons

Glycolysis

• Happens in cytoplasm

• Glucose (6 carbon) is split into 2 pyruvate molecules (3 carbon)

• No O2 requirement

• Requires 2 ATP

- Step 1 and 3

• Produces 4 ATP total

- 1 per pyruvate in step 7 and 10

• Produces 2 NADH molecules total

- 1 per pyruvate in step 6

Pyruvate

• 3 carbon molecule made out of the catatonic reaction of glucose

• Can be turned directly into lactate if no O2 present in body, anaerobic metabolism

• Can be moved to the mitochondria if O2 is present in body, aerobic metabolism

Linking Step

• Happens between the Glycolysis and Citric Acid Cycle steps

• Converts pyruvate into acetyl CoA

• Reduces NAD+ to NADH + H+ and gives off a CO2 per pyruvate

Citric Acid / Krebs Cycle

• Happens in mitochondria matrix

• Starts with acetyl CoA

• Produces 2 CO2, 1 ATP, 3 NADH + H+, 1 FADH2

Oxidative phosphorylation

• Made up of two simultaneous processes

- Electron transport chain

- Charismatic coupling mechanism

Electron transport chain

• Located in the inner membrane of the mitochondria

• Part of the oxidative phosphorylation step of glucose oxidation

• A sequence of electron carriers and proteins that move electrons in a deficient sequence through the mitochondrial membrane

- Chain of exergonic reaction, released energy is used to drive ATP synthesis

- Oxidized forms of NAD+ and FAD are also made by the chain

• Final acceptor of the electrons is O at the end of the chain

Charismatic coupling mechanism

• Part of the oxidative phosphorylation step of glucose oxidation

• Couples electron transport chain to ATP synthesis

• Energy produced by electron chain moves H protons from the matrix, against their concentration gradient, into the interstitial space

- H wants to move back with their concentration gradient to the matrix and does so through the fourth complex the ATP synapse

• When H diffuses back into matrix it releases energy that the ATP synapse harnesses and used to turn ADP into ATP

Glycogenolysis

• Alternative way to get glucose

• The act of breaking glycogen back down into glucose

• Done when there isn’t enough glucose in the blood

• Memory Hack: Ly = lice, genesis = to create '

- Lice to create

Gluconeogenesis

• Alternative way to get glucose

• The act of creating new glucose from noncarbohydrate-precursors such as glycerol, lactate, amino acids

- Liver does this

• Done when there isn’t enough glucose in the blood

• Memory Hack: gluco = glucose, genesis = to create

- To create glucose

Lipolysis

• Separation of fatty acid from glycerol molecule

Fat Metabolism

• Glycerol molecule are catabolized to acetyl CoA molecules by beta oxidation

- CoA molecules then enter the Krebs cycle

• Excess breakdown creates ketones which nervous system can use as a partial supplement to glucose

Protein metabolism

• Keto acids like pyruvate, acetyl CoA, Citric acid cycle intermediate

- Plugged into linking step of Krebs cycle

Proteolysis

• The break down of proteins to amino acids