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