AP Bio Unit 3: Cellular Energetics

Enzyme

Enzyme

A biological catalyst that speeds up biochemical reactions

• Proteins in tertiary formation

• Facilitates either synthesis or digestion reactions

Substrate

Molecule that interacts with an enzyme

Active Site

This part of the enzyme interacts with a substrate.

• Unique shape, size, and sometimes charge

Denaturation

Change in pH and temperature causes a change in the conformational shape of an enzyme

• Higher temperature or change in pH

Competitive Inhibitor

This molecule binds to an active site on an enzyme and prevents the substrate from binding to the enzyme, therefore slowing down or preventing reactions from occurring

Noncompetitive Inhibitor

This molecule binds to an allosteric site on an enzyme and prevents the substrate from binding to the active site of an enzyme, therefore slowing down or preventing reactions from occurring

Energy Coupling

Energy-releasing processes drive energy-storing ones

Entropy

Something all living things want to avoid: the tendency to head into chaos and disorder

Thylakoid

The light-dependent reaction of photosynthesis takes place in the _____

2 NADPH, 3 ATP

The light-dependent reaction in photosynthesis sends this to the Calvin Cycle

Proton Motive Force / PMF

the force that promotes movement of protons across membranes downhill the electrochemical potential

Light-Dependent Reaction

This happens in the thylakoid membrane of the chloroplasts and occurs in the presence of sunlight. The sunlight is converted to chemical energy during these reactions. The chlorophyll in the plants absorb sunlight and transfers to the photosystem which are responsible for photosynthesis

Light-Independent Reaction / Calvin Cycle

This is an assembly line to create glucose in photosynthesis. It happens in the stroma

PGAL

This is half of glucose, and the output of the Calvin Cycle

Fixation

During this stage of the Calvin Cycle, byproducts of the light reaction are used for carbon fixation (facilitated by RUBISCO)

Reduction

During this stage of the Calvin Cycle, 6 ATP is converted to 6 ADP and inorganic phosphate, while 6 NADPH is converted to 6 NADP+

(Everything gets oxidized)

6 PGAL are made in a high energy state

Regeneration

During this stage of the Calvin Cycle, 1 PGAL is released

5PGAL, 3Pi make RuBP which clamps down on CO2 to continue the cycle

Glycolysis

a set of reactions that converts glucose to pyruvate

• First step in metabolism in cellular respiration

Pyruvate

This is half of a glucose molecule, but it can also be used for other purposes

Krebs Cycle

This takes place in the mitochondria and does not need Oxygen

2 pyruvate —> 2 Acetyl CoA —> 4 CO2

1. Acetyl CoA from pyruvate oxidation merges with oxaloacetate

2. Citric Acid is formed

3. Citric acid is oxidized —> gives electron to NAD+ and 2 carbons are cleaved off

OUTPUT per glucose: 4CO2, 2 ATP, 6 NADH, 2 FADH2

Electron Transport Chain

a series of four protein complexes that couple redox reactions, creating an electrochemical gradient that leads to the creation of ATP in a complete system named oxidative phosphorylation

Fermentation

An anaerobic pathway for breaking down glucose, returning either lactate (animals) or ethanol (fungi/yeast)