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.
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