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

Mitochondrion Draw one and label the parts as shown below

Cristae

Things you will need to know… Formula for cellular respiration: O 2 + C 6 H 12 O 6 CO 2 + H 2 O + ATP Two hydrogen carrier molecules: –NAD (produces 3 ATP) –FAD (produces 2 ATP)

More on NAD and FAD NAD + 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 CO 2 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 Respiration where 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

Fermentation ALCOHOL Occurs in the cytoplasm Produces 2 alcohol, 2 CO 2, 2 NAD+ Makes only 2 ATP Many commercial uses LACTIC ACID Occurs in cytoplasm Produces 2 NAD+, 2 lactic acid, no CO 2 Makes only 2 ATP Causes muscle fatigue

Other Catabolic Pathways FYI 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