Cell parts and Processes

•-Surrounds the

cell

-Allows certain materials in

and out

The cell membrane

• Jelly-like filling inside the cell

• It is mostly water.

Cytoplasm

Nucleus -headquarters of the cell -regulates all cell activity -chromosomes inside

Control Center

…In the nucleus it looks like spaghetti!

But when you look closely its

- coiled tightly

-forms “X” shapes

Nucleus

Chromosomes

And if you look at it even more closely, you see that it is coiled up

DNA!

mitochondria

breaks down food to make ATP

Releases energy!

Vacuole:

Stores water and

other materials

Where plant cells trap sun light and

use it to make food for the cell.

photosynthesis

Chloroplast-plants only

Cell walls – plants only

Rigid structure surrounding plant cells.

Provides support for the plant.

• We have learned about some of the parts of a cell.

• Let’s see what they do to keep the cell or the organism alive.

• These “things they do” are

Cell Processes

Transport

• Materials have to get in and out of a cell to meet the cells needs.

• There are 6 ways this can happen

The cell membrane is semi- permeable, but not everything goes

through the same way.

Diffusion- movement of particles from an area of greater

concentration to an area of lesser concentration

• Examples:

• the scent of perfume, food or something less pleasant

• food coloring, dye, flavors you taste

Osmosis is diffusion, but it applies only to water.

Water always leaves an area

that’s more crowded with

water molecules, and goes to an area where it’s less crowded

with water molecules.

High concentration

of water molecules

Low concentration

of water molecules

OSMOSIS means:

In this picture a red blood cell is put in a glass of distilled water (all water with no salt or sugar in it). 

Because there is a higher concentration of water outside the cell, water enters the cell by OSMOSIS.

The cell bursts and dies

If it cant go through tiny openings, it goes through protein channels.

There are two ways this happens:

Passive transport and

Active transport

Passive transport- requires no energy (works with diffusion)

Active Transport- requires energy

(working directly against diffusion)

• But what if the cell wants to take something in or out that won’t fit through the tiny openings or the protein channels?

• There are two ways: Endocytosis and Exocytosis

Endocytosis (engulf) – for materials too big to fit in through cell

membrane

Exocytosis (opposite of Endocytosis) for materials too big to fit out through

cell membrane

Energy Production

• So where does the energy come from?

• There are two processes for energy production in plants:

Photosynthesis CO2 + H2O + sunlight = glucose + O2

and Cellular Respiration glucose + O2 = energy + H2O + CO2

Photosynthesis

•Plants take in carbon dioxide and sunlight

•make food for the plant (glucose)

•oxygen is released

Cellular Respiration• food and

oxygen meet in mitochondria

• food is broken down

• energy (ATP) is released

• carbon dioxide is released

Cell Reproduction

• As a cell gets bigger, the outside is unable to keep up with the inside, because the inside grows a faster rate than the outside.

• They have to reproduce (divide) to stay alive

• The 2 types of cell reproduction are Asexual (Mitosis)

and Sexual (Meiosis)

• Cell division in all cells except sex cells

Mitosis (asexual) One makes Two

• DNA of offspring is identical to parent cell

Meiosis (sexual reproduction) One makes Four

•This is how sex cells, such as sperm and ovum, divide

•Offspring that result from sexual reproduction between 2 parents have different DNA from their parents

Now you should know :

• 8 cell parts the name and job

• 10 cell process and what they involve

• If you don’t know those things, watch the PowerPoint again and take notes.