Cell Processes 1

1. Metabolism Cells obtain energy from their environment and then change it into a useable form It is the building up and breaking down of molecules of carbohydrates, lipids, proteins and nucleic acids (organic compounds made up of C,H,O,N,P)

Homeostasis Maintaining a stable internal environment 4

2. Diffusion Molecules of food, oxygen, and waste move in and out of the cell Moves across the selectively permeable cell membrane

Diffusion occurs when molecules move from an area of HIGH CONCENTRATION to an area of LOWER CONCENTRATION NO ENERGY REQUIRED

3. Osmosis It is the diffusion of water into or out of the cell Water molecules from HIGH to LOW concentration Does NOT require energy Occurs when there is an unequal concentration of water inside and outside the cell Maintains equilibrium

Salt Stinks!! Salt is a solute, when it is concentrated inside or outside the cell, it will draw the water in its direction. This is also why you get thirsty after eating something salty

PASSIVE TRANSPORT Diffusion and Osmosis are called passive transport because both require NO ENERGY

4. Active Transport Carrying a substance into or out of a cell NEEDS ENERGY (from the mitochondria) Against the concentration gradient Occurs when: The cell membrane is not permeable to a substance If the concentration is not high enough for diffusion to occur

Active Transport Continued… TRANSPORT PROTEINS are found in the cell membrane that transport molecules across the membrane Ex. Calcium, potassium, and sodium

5. Cellular Respiration Is the process of cells breaking down food molecules and releasing the energy they contain Occurs in the Cytoplasm and Mitochondria Simple food substances such as GLUCOSE are broken down, which releases energy

Cellular Respiration Occurs in 2 Stages Stage 1: In Cytoplasm: Molecules of Glucose are broken down into smaller molecules. Oxygen not involved, and only a little energy is released Stage 2: In Mitochondria: The small molecules are broken down further, with the help of oxygen and a great deal of energy is released

ATP Glucose has too much energy. It needs to be broken down into a smaller energy rich molecule called ATP (Adenine Triphosphate)

2 Types of Cellular Respiration Type 1: Aerobic Respiration Uses OXYGEN to to make energy (in the form of ATP) C 6 H 12 O 6 + 6O 2 ---> 6CO2 + 6H 2 O + ATP Glucose + Oxygen ---> Carbon Dioxide + Water + Energy Aerobic Respiration makes a total of 36 ATP every time

Type 2: Anaerobic Respiration Also called FERMENTATION: Energy is provided for the cells WITHOUT the use of Oxygen

Alcoholic Fermentation NO OXYGEN NEEDED Produce less energy C 6 H 12 O 6 ---> 6CO 2 + Alcohol + ATP Glucose ---> Carbon Dioxide + Alcohol + Energy

Lactic Acid Fermentation Occurs in muscles when use up oxygen in the cells C 6 H 12 O 6 ---> 6CO 2 + Lactic Acid + ATP Glucose ---> Carbon Dioxide + Lactic Acid + Energy “FEEL THE BURN”

6. Photosynthesis Photosynthesis: process by which a cell captures energy in sunlight and uses it to make food Chloroplasts- contain chlorophyll. The main photosynthetic pigment. Acts as a solar cell to capture energy. 22

2 stages of photosynthesis 1. Capturing Suns Energy- chloroplasts capture suns energy 2. Using Energy to make Food- Water, Carbon Dioxide and the energy are used to create food and waste product oxygen

Equation 6CO 2 + 6H > C 6 H 12 O 6 + 6O 2 Carbon Dioxide + Water -----> Glucose + Oxygen

Comparing Photosynthesis and Respiration