Cell ProcessesMovement Across Cell Membrane

Photosynthesis

Cellular Respiration

Transporting/Moving Substances Across the Cell Membrane

Cell Membrane

• Regulates what enters and exits the cell

• Provides protection and support

• Semi-permeable – allows small substances through and keeps larger substances out

• Cell Membrane is made of lipids and proteins

Types of Movement through the Cell Membrane

• Active Transport

• Passive Transport

Passive Transport

• Diffusion – substance moving from an area of high concentration to an area of low concentration

• Concentration means the amount substance in a given area

• No energy required

Passive Transport

• Osmosis – diffusion of water through the cell membrane

Effects of Osmosis

• Water will move in the direction where there is a high concentration of solute (low concentration of water )

• Salt Sucks – 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.

Effects of Osmosis

Isotonic Solution

If the concentration of solute (salt) is equal on both sides, the water will move back in forth but it won't have any result on the overall amount of water on either side.

"ISO" means the same

Hypotonic Solution

The word "HYPO" means less, in this case there are less solute (salt) molecules outside the cell, since salt sucks, water will move into the cell.

The cell will gain water and grow larger. In plant cells, the central vacuoles will fill and the plant becomes stiff and rigid, the cell wall keeps the plant from bursting

Hypertonic Solution

• The word "HYPER" means more, in this case there are more solute (salt) molecules outside the cell, which causes the water to be sucked in that direction.

• In plant cells, the central vacuole loses water and the cells shrink, causing wilting.

• In animal cells, the cells also shrink.• In both cases, the cell may die.

Active Transport

Movement through a membrane that requires energy

Photosynthesis

AUTOTROPHS

• Living things depend on energy to exist.

• Organisms that make the own food are autotrophs

• Plants and some other types of organisms are able to use the light energy from the sun to produce food.

Photosynethesis

• The process that coverts inorganic substances, CO2 and H2O, using the sun’s energy into an organic substance called glucose, C6H12O6 and a waste product,O2.

• Chlorophyll – plants principal pigment that absorbs sunlight

PHOTOSYNTHESISEQUATION

Leaf Parts

• Stoma (stomata) – small pores that act as a doorway for gases involved in photosynthesis (found mainly on the underside of leaves).

• Guard Cells – cells that regulate the opening of the stomata.

• Lower and upper epidermis – outer layer of a plant that serves for protection, like skin.

Stoma Open vs. Closed

• Open – with light and when guard cells are filled with water.

• Closed – without light and when guard cells are lacking water (dehydrated).

• Why is it important to have stomata open?

Closed vs. Open

Stomata Open vs. Closed

-Water -No Water -Light -Dark

Why is it important to have stomata open? GAS EXCHANGE for photosynthesis!

• When stomata are open gas exchange important for photosynthesis can occur.

• O2 can diffuse out and CO2 can diffuse in.

• Water can evaporate as well (transpiration)

FACTORS THAT EFFECT PHOTOSYNTHESIS

• AMOUNT OF WATER

• TEMPERATURE

• INTENISTY OF LIGHT

CELLULAR RESPIRATION

Cellular Respiration

Define cellular respiration

• A process that releases energy by breaking down food molecules in the presence of oxygen

• Plants make their own food (photosynthesis) and animals (heterotroph) must obtain their own food.

• Both plant and animal cells must undergo cellular respiration

• Process occurs in the mitochondria

Chemical Equation for Cellular Respiration

• The equation is the opposite of photosynthesis.

CHEMICAL ENERGY AND ATP

• The activities of the cell are powered by chemical fuels. One of the principal chemical compounds that living things use to store energy is Adenine Triphosphate – ATP.

ATP• One glucose molecule breaks down into about 36 ATP

molecules• ATP is a fully charged battery, ready to power the

machinery of the cell.

Energy

• Cells use energy for

– Active transport – Movement within the cell– Activities in the cell