Microtubules - hollow, support, intracellular transport, cell division, formation of microvilli, cilia and flagella.
What is the cell membrane?
Aka plasma membrane.
1. Phospholipid bilayer
2. Protein transporter
4. Carbohydrate molecule
5. Phospholipid polar head (hydrophilic)
6. Phospholipid fatty aid tail (hydrophobic)
What is the role of cholesterol in the cell?
Packer in cell membrane - gives cell its shape.
What is a glycoprotein?
A carbohydrate attached to a protein.
What is a passive transport process?
Transport relies on pressure, concentration differences and kinetic energy. moves down the concentration gradient. No ATP is used.
Simple diffusion, osmosis, filtration and facilitated diffusion.
What is an active transport process?
Active transport requires the use of ATP and can move substances through protein pumps against the concentration gradient.
Bulk transport process includes phagocytosis, pinocytosis, endocytosis and exocytosis and also requires ATP
Outline simple diffusion.
Particles move from an area of their own high concentration to an area of their own low concentration until equilibrium is reached.
Particles move down the pressure gradient.
What increases the rate of diffusion?
Concentration difference is greater.
What particles can diffuse through the phospholipid bilayer?
Fat soluble vitamins (D,E,K,A also B,C)
Water passing through a semipermeable membrane from an area of high concentration of water to an area of low concentration of water.
Relative concentration of solutes.
Two solutions that have the same concentration of water and solutes.
High concentration of solutes, therefore a low concentration of water.
What happens to the volume of a RBC if it was placed in to a hypertonic solution.
The water concentration would be higher inside the cell than in the solution, so the water inside the cell would transfer out of the cell through osmosis, therefore reducing the volume of the RBC.
Known as crenation.
Low concentration of solutes, therefore a high concentration of water.
What happens to the volume of a RBC if it was placed into a hypotonic solution?
The water concentration would be lower inside the cell than in the solution, so the water outside the cell would be transferred into the cell through osmosis, therefore increasing the volume of the RBC. Known as haemolysis.
Outline facilitated diffusion
The movement of particles from an area of high concentration to an area of low concentration with the aid of protein transporters.
What is an example of a particle that is transported by facilitated diffusion?
Insulin opens a "gate" in the protein transporter to speed up the rate at which glucose is taken into the cell.
Driven by water pressure. Water, and dissolved substances are pushed through the membrane from an area of high pressure to area of low pressure. eg. kidneys.
Give an example of a membrane pump that requires ATP.
Sodium/potassium pump. Uses ATP to get sodium ions into the cell and potassium ions out of the cell. It can do this against the pressure gradient.
Name the two bulk transport processes.
What is endocytosis?
A bulk transport process.
The intake of materials in bulk into the cell.
Endocytosis bulk transport
Cell extends its membrane around the particle it is going to ingest. Once surrounded by membrane, particle is taken into the cell in the form of a vesicle.
Endocytosis bulk transport
The cell forms a pocket for fluid to flow into. a vesicle is then formed. (pinocytotic vesicle)
Bulk transport process
Removal of substances from the cell into extracellular fluid.
A vesicle made by the Golgi body fuses with cell membrane and the contents are expelled.
3. Nuclear envelope
4. Nuclear pore
2. Nuclear pore
3. Rough Endoplasmic Reticulum
4. Transport vesicles
5. Golgi apparatus
6. Secretory vesicles
Describe organic compounds.
What are the organic compounds in the human body?
Always contain carbon
Held together by strong chemical bonds
Can be made by living organisms
Carbohydrates, lipids, proteins and nucleic acids (DNA & RNA)
D. Nucleic acid
A. Monosaccharide - Simple sugars
B. Disaccharide - Simple sugars
C. Polysaccharide - Complex sugars and starches
Come from plants
Made of carbon, hydrogen and oxygen.
Sugars and starches.
Names often end in -ose.
Three main groups:
One unit sugar.
Building blocks of more complex sugars and starches.
Pentoses & Hexoses
5 carbon sugars - pentagon shape
- Deoxyribose (in DNA)
- Ribose (in RNA)
6 carbon sugars - hexagon shape
- Galactose (component of lactose)
Describe disaccharides. How many are there? What are their names?
Two unit sugar.
Must be digested to monosaccharides before they can be absorbed into blood stream.
Maltose = Glucose + Glucose
Sucrose = Glucose + Fructose
Lactose = Glucose + Galactose
Where are the three disaccharides found?
Maltose - fruits and barley
Fructose - table sugar and fruits
Lactose - milk
What enzyme digests sucrose and what are the products?
Sucrase = Glucose + Fructose
What enzyme digests lactose and what are the products?
lactase = glucose + galactose
What enzyme digests maltose and what are the products?
maltase = glucose + glucose
What organ can convert galactose and fructose to glucose?
Outline polysaccharides and name them.
Very large molecules, hundreds of glucose molecules linked together.
Starch, Glycogen, Cellulose
Made by plants to store energy.
Two step digestion process.
Name the enzymes, intermediate and final products of starch digestion.