Keystone Review 3: Photosynthesis & Cellular Respiration

Cellular energy is called ATP (Adenosine triphosphate)

ATP stores a small amount of energy

ATP is the cell’s energy currency used for almost all cellular activities 

The bond is broken on the last phosphate group to release a small amount of energy.  ADP is the left over molecule.

During cellular respiration, phosphates are added back to ADP molecules to remake ATP.

The energy to do this comes from carbohydrates (sugars).

This is done in the mitochondria.

The cell membrane is selectively permeable, meaning only certain substances can pass through

Small or nonpolar molecules can pass through (i.e. water)

Large or polar molecules cannot pass through without help (i.e. proteins)

Passive transport does NOT require energy for substances to move across the cell membrane. Substances move from HIGH to LOW concentrations

Homeostasis is the regulation of metabolic processes to maintain the stable internal conditions required for survival.

Types of Passive Transport:

• diffusion

• facilitated diffusion

• osmosis (hypertonic, hypotonic, isotonic)

Active transport DOES require the use of energy to move substances across the cell membrane. Substances move from LOW to HIGH concentrations

Types of Active Transport:

• endocytosis

• exocytosis

• membrane pumps

Process of transforming solar energy gathered from sunlight into the chemical energy of glucose sugar.

Occurs in the chloroplast of plant cells

Two-step process:

• Light Dependent Reaction - occurs in thylakoid

• Light Independent Reaction (Calvin Cycle) - occurs in stroma

Reactants: carbon dioxide, water, sunlight

Products: glucose, oxygen

Process of transforming the chemical energy from food (sugar) into the chemical energy of ATP molecules

Occurs in the mitochondria of cells

Three-step process:

• Glycolysis - occurs in cytoplasm

• Krebs Cycle - occurs in the matrix of the mitochondria

• Electron Transport Chain - occurs in the inner membrane of the mitochondria

Reactants: glucose, oxygen

Products: carbon dioxide, water, ATP