Cell Transport

Organic Compounds Carbohydrates Sugars – fruits and vegetables Starches – potatoes, pasta, rice, bread Break down into glucose (sugar) and used to produce energy.

Lipids – fats, oils and waxes Rich in energy Stored energy for later use Cell membrane – made of lipids

Meats, eggs, fish, nuts, beans                                                                                                                                                                  Proteins – amino acids H O N C 20 common amino acids Different amino acids Different arrangement Change the type of protein formed Meats, eggs, fish, nuts, beans

Enzyme – kind of protein Used to speed up chemical reactions in the body Each enzyme has a special job Ex. Saliva – speeds up breaking down of starches into sugar in your mouth

How enzymes work. 1.They are organic proteins 2.Enzymes are specific; they only react with specific substances that examples: Lipase (an enzyme) will only react with lipids(fats,oils), Amylase will only react with starch,etc. 3. After they do their job, the same enzyme can be used over and over again

Nucleic acids – very long organic substances C H O N P Instructs cells on functions of life DNA – passes down info about organism from parent to offspring RNA – helps in production of proteins - found in nucleus and cyto

Control of materials by cells Selective permeablility – the ability of the cell membrane to allow some materials in and keep others out.

Diffusion As they move, they move from higher concentration to places of lower concentration.

Equilibrium - Diffusion occurs until all of the particles are evenly distributed. - keep on moving but maintain that equilibrium

osmosis The diffusion of water through the cell membrane. Osmosis is impt b/c 1. Cells contain water mole. 2. Most cells are surrounded by water molecules Water moves from higher concentration to lower concentration

Osmosis Equilibrium exists when water leaves and enters the cells at the same rate.

Types of transport                                      OSMOSIS Passive transport – movement of particles across cell membrane by diffusion. - cell does not need to use energy to move the particles.

Facilitated diffusion Protein molecules located in the cell membrane help larger molecules that normally can’t enter the cell membrane. Carrier proteins Passive transport They act as a gate to let lg mole into the cell

Facilitated Diffusion Facilitated diffusion involves the use of a protein to facilitate the movement of molecules across the membrane.  In some cases, molecules pass through channels within the protein.                                              

Active transport When the cell uses energy to pass molecules through cell membrane. Movement occurs from areas of low concentration to areas of high concentration. Carrier proteins used Opposite of diffusion

Proteins in the Membrane Active transport is usually done across the cell membrane. Embedded in the lipid bilayer are proteins. The proteins are very specific. One protein that moves glucose will not move calcium (Ca) ions. There are hundreds of types of carrier proteins.

Protein joins with the particle to be transported. Energy from cell is used to move the particles. Active transport

Endocytosis Some molecules are too large to pass through the cell membrane by active or passive transport. Large proteins and bacteria enter the cell by becoming enclosed in a part of the cell membrane that folds in to form a sphere The sphere pinches off- vacuole is made and contents enter cyto

Exocytosis Substances in small sacs are released at the cell membrane. The vesicle fuses with the cell membrane and its contents released from the cell.

exocytosis