Energy For The Cell

ATP, Photosynthesis, and Cellular Respiration

Energy • Ability to do work (chasing prey,

finding shelter and mate)

ATP=ENERGY • Adenosine triphosphate• Energy storage molecule• 1 cell uses 1 billion ATP per minute• Made of

– 3 phosphates– ribose (sugar)– adenine (nucleotide

How Energy is Released From ATP

• When energy is needed– ATP ADP – Breaks a chemical bond

• After energy is used, ADPADP– Picks up a free loading phosphate

• ATP/ADP CYCLE

Living Things• Autotrophs = producers

– Plants and some bacteria– Make their own food (glucose)– Photosynthesis or chemosynthesis

Living Things • Heterotrophs = consumers

– Organisms that have to eat or obtain food for energy

– Herbivores – eat plants– Carnivores – eat other animals– Omnivores – eat both– Detritivores – eat dead matter

Photosynthesis • Using light, CO2, and H2O to make

food (glucose)• Sugar and oxygen are released• Organisms with pigments for

capturing the energy from light– Chlorophyll (green)

Photosynthesis Equation

Where Does It Take Place?• Photosynthesis takes place in the

chloroplast (collects light energy)– Many in each cell of the leaves– Thylakoids – disk or pancake shape

• Grana – stacks of thylakoids– Stroma – gel –like fluid around

thylakoids

2 Reactions of Photosynthesis

1. Light Reaction (Light dependent)– Occurs in the thylakoid– Light is absorbed– H2O is split– Oxygen is released– Electrons move through the Electron

Transport Chain (ETC)– NADPH and ATP made

2. Dark Reaction (Light Independent)– Calvin Cycle– Occurs in stroma– NADPH and ATP (released in light

reaction) used to “fix” CO2 into

glucose

Cellular Respiration • Breaking down food molecules to

release energy (MAKES ATP)• Glycolysis is the first process in

breaking down glucose – Takes place in the cytoplasm of a cell– Changes glucose into 2 pyruvate– 2 ATP used, 4 ATP made (net of 2ATP)

Two Types of Cellular Respiration (after glycolysis)1. Aerobic Respiration

– Takes place in the MITOCHONDRIA– Occurs when Oxygen is present– Pyruvate from glycolysis is broken

down into CO2 and Water– Has 2 parts Kreb’s cycle and ETC– Makes 36 ATP from 1 glucose

molecule

2. Anaerobic Respiration– Break down of pyruvate without

OXYGEN– Occurs in cytoplasm– Does not produce many ATP– Two kinds

• Lactic Acid Fermentation• Alcohol Fermentation

Alcoholic Fermentation • How we make beer, wine and

some breads• Starts with pyruvate

• End Products:2 - ATP2 - CO2

2 - Ethanol’s

Lactic Acid Fermentation • Makes our muscles sore if we work

out too much• Starts with pyruvate• End Products:

– 2 – ATP– 2 - Lactic Acids

Respiration Equation C6H12O6 + O2 CO2 + H2O

ATP released

Final Accounting • The breakdown of glucose nets a

TON of energy for the cell.• We can harvest a total of 36 ATP per

molecule of glucose.

• Remember that extremely active cells need tons of energy from the mitochondria.