Biology Honors

First, a little about ATP• ATP– the energy that our cells

use• Cells use glucose to make

ATP• When the cell needs energy, it

breaks ATP• When ATP breaks, you get

ADP and energy• ADP gets a new phosphate,

becomes ATP again• Like charging a battery

ATP Cycle

The Mitochondrion

• Powerhouse of the cell

• Takes glucose and makes usable energy cellular ATP

• CELLULAR RESPIRATION

MitochondrionDraw one and label the parts as shown below

Cristae

Things you will need to know…

• Formula for cellular respiration:

• O2+ C6H12O6 CO2 + H2O + ATP

• Two hydrogen carrier molecules:– NAD (produces 3 ATP) – FAD (produces 2 ATP)

More on NAD and FADNAD + H = NADH

NADH - H=NAD

FAD + H= FADH

FADH - H=FAD

Cellular Respiration: Step 1• Glycolysis

Gly= refers to sugar

lysis= to break

Glycolysis: breaking sugar• Occurs in the cytoplasm

• 2 ATP molecules break glucose (6C) into two 3 carbon molecules

• Pyruvate or Pyruvic Acid (-ate / -ic = acid)

• 4 ATP are released in the end

• Hydrogen is released and picked up by NAD

Glycolysis: products

Per glucose molecule:

• ATP: make 4, use 2…..net gain = 2 ATP

• NADH: 2 NAD to 2 NADH

• Pyruvic acid: 2 (three carbon molecules)

Cellular Respiration: Step 1A

• Intermediate Step or the “Prep Step”

• Occurs only in presence of oxygen (Aerobic)

• Pyruvate loses one carbon, becomes acetyl-CoA

• Carbon dioxide is released

• NAD picks up hydrogen

Cellular Respiration: Step 2• Occurs in mitochondrial

matrix• Krebs Cycle or Citric Acid

Cycle• Acetyl CoA enters the cycle• Carbons are removed in

steps and released as 4 CO2

• 6 NADH & 2 FADH formed

• 2 ATP made

Cellular Respiration: Step 3• Electron Transport

Chain

• Occurs in inner membrane folds (cristae)

• NADH and FADH drop off hydrogen

• Oxygen picks up hydrogen, forms water

• 30 ATP made

Aerobic Respirationwhere it all happens

• Cytoplasm– glycolysis

• Matrix– Krebs

Cycle

• Inner membrane (cristae)– ETC

Anaerobic Respiration = NO OXYGEN

• AKA – Fermentation

• Only glycolysis occurs

• Pyruvic acid converts to lactic acid or ethanol (ethyl alcohol)

• Alcoholic fermentation—occurs in plants

• Lactic acid fermentation—occurs in animals

FermentationALCOHOL• Occurs in the

cytoplasm • Produces 2 alcohol, 2

CO2, 2 NAD+

• Makes only 2 ATP• Many commercial

uses

LACTIC ACID• Occurs in cytoplasm• Produces 2 NAD+, 2

lactic acid, no CO2

• Makes only 2 ATP• Causes muscle fatigue

Other Catabolic PathwaysFYI Only (Don’t write this!)

• Polysaccharides– First broken down into simple sugars– Enter glycolysis

• Fats– Broken down into 2 carbon molecules and

converted to acetyl coA– Enter Krebs cycle

• Proteins– Amino group removed, broken down into 2-

carbon molecules of acetyl CoA– Enter Krebs cycle

Photosynthesis & Cellular Respiration