Photosynthesis & Cellular Respiration Chapter 4.2, 4.4, 4.6 Reaves 17-18

Photosynthesis A process that captures energy from sunlight to make sugars that store chemical energy Occurs within the chloroplast Chlorophyll (in chloroplast) absorbs energy in visible light Chlorophyll reflects green light!

Photosynthesis Photosynthesis takes place in two parts of chloroplasts. grana (stack of thylakoids) Stroma (chloroplast fluid)

Photosynthesis There are 2 stages of photosynthesis Light Dependent Reactions (uses light) (Light Reactions) Light Independent Reactions (doesn’t use light) (Dark Reactions)

Photosynthesis The light-dependent reactions capture energy from sunlight. take place in thylakoids water and sunlight are needed chlorophyll absorbs energy energy is transferred along thylakoid membrane then to light-independent reactions (dark reactions) oxygen is released

Photosynthesis The light-independent (dark) reactions make sugars. take place in stroma needs carbon dioxide from atmosphere use energy from light reactions to build a sugar in a cycle of chemical reactions

Photosynthesis

The overall process of cellular respiration converts sugar (glucose) into ATP (energy) using oxygen.

Aerobic stages take place in mitochondria (animal and plant cells) Cellular Respiration makes ATP by breaking down sugars (that we consume and plants produce). aerobic (requires O2) Aerobic stages take place in mitochondria (animal and plant cells) mitochondrion animal cell

Cellular Respiration = pyruvate Glycolysis must take place first. - anaerobic process (does not require oxygen) - takes place in cytoplasm - splits glucose into pyruvic acid (or pyruvate) - Glucose has 6 C’s and pyruvic acid is two 3 C’s - produces two ATP molecules = pyruvate

Cellular respiration The Krebs cycle transfers energy to an electron transport chain. takes place in mitochondrial matrix breaks down pyruvic acid from glycolysis makes a small amount of ATP releases carbon dioxide transfers energy-carrying molecules

Cellular respiration The electron transport chain produces a large amount of ATP. takes place in inner membrane energy transferred to electron transport chain oxygen enters process ATP produced water released as a waste product

Cellular respiration C6H12O6 + 6O2  6CO2 + 6H2O + ATP sugar oxygen carbon water energy dioxide

Cellular respiration is like a mirror image of photosynthesis. The reactants in photosynthesis are the same as the products of cellular respiration.

Fermentation Fermentation occurs in place of cellular respiration when oxygen is NOT present.

Fermentation Fermentation is an anaerobic process. - occurs when oxygen is not available for cellular respiration - does not produce ATP, but allows glycolysis so it can make a small amount of ATP.

Fermentation

Fermentation There are two types of fermentation: Lactic Acid and Alcoholic

Fermentation Lactic acid fermentation occurs in muscle cells. glycolysis splits glucose into two pyruvate molecules pyruvate is converted into lactic acid Lactic acid causes soreness in muscles

Fermentation Alcoholic fermentation is similar to lactic acid fermentation. glycolysis splits glucose into two pyruvate molecules pyruvate is converted into alcohol and carbon dioxide alcoholic fermentation takes place in yeast and some plants

Fermentation Fermentation is used in food production. yogurt cheese bread