ATP

ATP & ADP  ATP: Adenine triphosphate  adenine + ribose + 3 phosphates  Energy storing molecule, only stores energy for a few minutes  Source of all cell energy – “currency” of the cell; different cell functions require different amounts of ATP Adenine Ribose 3 Phosphate groups

ATP – ADP CYCLE  When one phosphate group breaks off, energy for cell work is released  ADP can reform into ATP by bonding another phosphate group

 ADP: Adenosine diphosphate  Adenine + ribose + 2 phosphates  Molecule that results from ATP losing one P ADP ATP Energy Partially charged battery Fully charged battery Adenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)

How do cells use energy in ATP?   When the phosphate bond is broken, the cell can use the released energy for different processes:   In photosynthesis, for making glucose   making new molecules - such as enzymes, cell membrane components, organelles, etc.   to maintain homeostasis, transmit nerve impulses, move cilia, remove wastes, etc.

ATP – ADP cycle in cells   In photosynthesis:   ATP is PRODUCED during Light-dependent reactions   ATP is USED during Dark-dependent reactions to make sugar and sustain plant cell functions   In cell respiration:   ATP is PRODUCED when breaking down sugars from food   ATP is USED to sustain cell functions

PHOTOSYNTHESIS, RESPIRATION, FERMENTATION

Photosynthesis  process using energy from sunlight to convert water and CO 2 into oxygen and carbohydrates (sugar)  Two parts:  Light dependent reactions: produce O 2 & converts ADP to ATP  Calvin cycle (dark reactions): use ATP from light reactions to produce sugars

 Chlorophyll: green pigment inside chloroplasts in plant cells that absorbs blue & red light energy  Moves energy to electrons that drive reactions Chloroplast Light- Dependent Reactions Calvin Cycle Sugars

Overview cellular respiration  Respiration: process that releases energy by breaking down food when oxygen is present  Formula:  C 6 H 12 O 6 + O 2  CO 2 + H 2 O

 Fermentation: respiration without oxygen present  Two types:  Alcoholic: form ethyl alcohol and CO 2 as waste products; used to make bread rise  Lactic acid: produces lactic acid in muscles when exercising without enough oxygen

How photosynthesis & respiration relate.  Almost opposite processes  Photosynthesis produce food (store)  Respiration breaks down food (releases)  Photosynthesis uses CO 2 and releases O 2  Respiration releases CO 2 and uses O 2

Quiz 4 1.The formula CO 2 + H 2 O --- C 6 H 12 O 6 + O 2 is the formula for ? a. photosynthesis b. respiration 2.___ is the process which breaks down food molecules to release energy and takes place in the mitochondria. a. photosynthesis b. digestion c. respiration 3.___ is formed when ATP releases a phosphate. a. ADP b. AMP c. APP 4.Fermentation is a form of ___ respiration which occurs without the presence of oxygen. a. aerobic b. anaerobic c. antioxidant 5.The green pigment which is present in plant cells and allows them to go through photosynthesis is ___. a. chlorophyll b. chloroplast c. chlorosis