Cellular Transportation

&

Respiration

Passive Transport

• A cell membrane is

semiperamble, which means that

it allows only certain substances to

enter or leave a cell.

• Passive transport is the movement

of substances through a cell

membrane without using the cell’s

energy.

Diffusion

• Diffusion is the movement of

substances from an area of

higher concentration to an area

of lower concentration.

• Usually diffusion continues

through a membrane until the

concentration of a substance is

the same on both sides of the

membrane.

Osmosis

• Osmosis is the diffusion of water molecules only through a cell membrane.

• If the concentration of water in the air surrounding a plant is less than the concentration of water inside the plant’s vacuoles, water will diffuse into the air until the concentration of water is equal.

• Facilitated diffusion occurs when

molecules pass through a cell membrane

using special proteins

called transport proteins.

• Carrier proteins are transport proteins

that carry large molecules through the

cell membrane.

• Channel proteins are transport

proteins that form pores through the

cell membrane.

Active Transport

• Active transport uses the cell’s

energy to move substances

through a cell membrane.

• Active transport moves

substances from areas of

lower concentration to areas

of higher concentration.

Active Transport

• A cell uses endocytosis to take in a

substance too big to pass through

the cell membrane.

• A cell’s vesicles release their

contents outside the cell during

exocytosis.

Cell Size and Transport

• For a cell to survive, its surface area

must be large compared to its

volume.

• As a cell grows, its volume

increases faster than its surface

area.

diffusion osmosis

Facilitated

diffusion

endocytosis exocytosis

Cellular Respiration

• All living things need energy to

survive.

• Cellular Respiration is the process

in which organisms break down

food to release energy.

Cellular Respiration

• The first step of cellular respiration,

called glycolysis, occurs in the

cytoplasm of all cells.

• During glycolysis glucose, a sugar, is

broken into smaller molecules.

• The second step of cellular

respiration occurs in the

mitochondria of eukaryotic cells.

This step requires oxygen.

Cellular Respiration

• During the 2nd step of cellular respiration, the smaller molecules made during glycolysis are broken down. Large amounts of usable energy, called ATP, are produced.

• Water and carbon dioxide (CO2) are two waste products that are given off during the 2nd step of cellular respiration.

Fermentation

• Fermentation is the process that

releases energy without using oxygen.

• Eukaryotic and prokaryotic cells use

fermentation to obtain energy from

food when oxygen levels are low.

• Fermentation occurs in the a cell’s

cytoplasm.

Fermentation

• Lactic-acid fermentation converts

glucose into ATP and a waste product

called lactic acid.

• Some types of bacteria and yeasts

make ATP during alcohol

fermentation. The process produces

alcohol/ethanol and CO2

Photosynthesis

• Plants and some unicellular organisms obtain energy from light.

• Water, carbon dioxide (CO2), and chlorophyll are involved in photosynthesis.

• In plants, light energy is absorbed by pigments such as chlorophyll.

Photosynthesis

• The chemical reactions of photosynthesis

occur in chloroplast, the organelles in plant

cells that convert light energy into food.

• Photosynthesis uses CO2 that is released

during cellular respiration to make food

energy and release oxygen (waste

product).

• When an organism eats plant material, it

takes in food energy. An organism’s cells

use oxygen released during photosynthesis.

reactions in

cytoplasm

reactions in

mitochondria

reactions in

chloroplasts

carbon

dioxide

water

oxygen

carbon

dioxide

light energy