cellular process

CellularProcesses

T- 1-855-694-8886Email- [email protected]

By iTutor.com

http://www.itutor.com/


Cellular Processes - Homeostasis

• Homeostasis is maintained on an individual level, by the semi-permeable membrane surrounding the cell called the plasma membrane.

• This membrane is made of a thin layer of long chained phospho - lipids.

• Lipids are fats and the plasma membrane is semi-water repellent.

© iTutor. 2000-2013. All Rights Reserved


Diffusion

• Molecules move across the cell membrane by a process called diffusion.

• Diffusion is the movement of molecules from areas of greater concentration to areas of lesser concentration.



Diffusion• Molecules move into or out of the cell

until there is an equal number on both sides of the cell membrane.

• Water molecules are small enough to pass through the cell membrane by diffusion.

• Osmosis is the diffusion of water across the cell membrane.



Cellular Processes - Permeability

• The permeability of a membrane is the rate of passive diffusion of molecules through the membrane.

• These molecules are known as permeant molecules



Transportation of Molecules

• Larger molecules like sugars, starches, and proteins sometimes diffuse through protein channels.

Active Transport

• Active transport is a process that allows molecules to move across the cell membrane from lower to higher concentrations.

• To do this requires energy.© iTutor. 2000-2013. All Rights Reserved


Transportation of Molecules

• A cell can take in large particles of food by “engulfing” them.



Cells and Energy



What is photosynthesis?• Photosynthesis is a chemical reaction

that takes place in the chloroplasts of plant cells.

• During photosynthesis, plants use the energy of sunlight to produce energy-rich molecules called carbohydrates (ex. glucose).

In photosynthesis, plants take in carbon dioxide and water and release glucose and oxygen wastes.

• Chloroplasts are where photosynthesis occurs.

• Chloroplasts work much like solar cells found in calculators.



Chlorophyll• A pigment is a molecule that absorbs

some colors of light and reflects others.

• Chlorophyll is the main pigment used in photosynthesis.

• Chlorophyll absorbs mostly blue and red light, and reflects green light.

• This is why most plants look green.



Cellular Respiration• Cellular respiration is a chemical

reaction that occurs in all living things. • Cells use oxygen and glucose to

produce carbon dioxide, water, and energy.

• In most eukaryotic organisms, cellular respiration takes place in the mitochondria of cells.

• During cellular respiration, energy is stored in a molecule called ATP while some energy is released as heat.



Disposal of Wastes• A living cell uses a number of

different chemical reactions to survive.

• These processes create a large amount of waste that the cell needs to remove.

• This includes the byproducts of reactions designed to burn energy, as well as toxic metabolites such as reactive oxygen species.



The End

Call us for more Information:

www.iTutor.com

1-855-694-8886

Visit



cellular process

Education