Key concepts in Biology Flashcards
Key Parts of an animal cell
Nucleus, Cell membrane, Cytoplasm, Mitochondrion, Ribosomes
What Type of cell is an Animal cell?
Eukaryotic
What type of cell are Bacteria?
Prokaryotic - with no membrane bound nuclei
Key Parts of a plant cell
All of the animal cell parts + Vacuole, Cell wall, Chloroplasts
Purpose of cell wall
To keep plant rigid
Purpose of vacuole
To help keep the cell swolen - filled with cell sap
Parts of a bacteria
Flagellum, Chromosomal DNA, Plasmid DNA, Cell wall
How does a bacteria reproduce?
They divide by binary fission - similar to mitosis but much simpler
Specialized animal cells
Sperm - Enzymes in head to break through egg wall, Midpiece containing lots of mitochondria, tail for swimming
Egg - Nutrients for growth of early embryo.
Ciliated Epithelial Cell - Mucus and cilia on surface to move fluids and particles up the trachea.
Types of microscope
Electron and Light
Whats the Difference between the two microscopes?
Electron microscopes provide higher magnification and resolution but cannot be used on living cells
Light microsopes can be used for studying living cells and for low magnification work.
EQUATION FOR MAGNIFICATION
Magnification = SIZE OF IMAGE DIVIDED BY REAL SIZE OF OBJECT
Why cant electron microscopes be used on living samples?
The samples must be placed in a vacuum
Enzymes
Proteins that function as biological catalysts.
Lock and key Hypothesis
Enzyme is a particular shape
Active site is a place where enzymes fit
Both the shape of the substrate and the active site match.
What happens when an enzyme is exposed to extremes of PH or Temperature?
It will denature and not function as expected.
Rate of reaction equation
Amount of substrate used or amount of product formed DIVIDED BY time taken.
KEY PRACTICAL: PH ON ENZYME ACTIVITY
- Set up bunsen burner
- Place beaker of water at 35 Degrees
- Put iodine onto each spot on a spotting tile
- Add 2cm^3 of amylase
- Add 2cm^3 of starch
- Add 1cm^3 of PH solution into tube
- Heat with bunsen
- Put each drop of solution into test tube every 20 secs
- Repeat until iodine stops turning black, record time taken.
Diffusion
Particles in a gas or liquid will spread to fill their available container. They will always move - but end up evenly spread through the liquid or gas
Osmosis
Water molecules moving in and out of a cell WITH THE CONCENTRATION GRADIENT. This is a passive process that requires no energy
Active transport
Moving nutrients etc AGAINST THE CONCENTRATION GRADIENT: This uses energy.
Define Plasmolysis
When a solution inside a cell becomes very concentrated, the cell membrane pulls away from the cell wall completely.
