Chapter 1 Flashcards
Eukaryotic cells - Plant & animal cells
Have a nucleus.
Prokaryotic cells
Don’t have a nucleus, chloroplasts or mitochondria.
Orders of magnitude
Used to make approximate comparisons.
One order of magnitude = 10
Two order of magnitude = 100
Parts of a plant cell
- Cell membrane
- Ribosomes
- Cell wall/cellulose
- Mitochondria
- Cytoplasm
- Vacuole
- Chloroplasts
- Nucleus
Functions of the cell membrane
Controls what comes in and out of the cell
Functions of the ribosomes
Where proteins are made
Functions of the cell wall
Supports and strengthens the cell
Functions of the mitochondria
Where most of the aerobic respiration reactions take place
Functions of the cytoplasm
Where most chemical reactions happen, contains lots of enzymes to control these reactions
Functions of the vacuole
Contains cell sap
Functions of the chloroplasts
Where photosynthesis occurs
Functions of the nucleus
Controls cell activities and holds DNA
Magnification calculations
size of image ÷ size of real object
size of real object X magnification
magnification ÷ size of image
Cell differentiation
Cell differentiate to become specialised
- Stem cells
- Cardiac cells
- Nerve cells
- Blood cells
- Muscle cells
- Intestinal cells
- Liver cells
Specialised cells
- Nerve cell
- Muscle cell
- Sperm cell
- Xylem cell
- Phloem cell
- Root hair cell
Functions of specialised cells
- Nerve cell: Carry electrical signals around the body
- Muscle cell: To contract
- Sperm cell: Fertilise egg cells
- Xylem cell: Transport water & minerals
- Phloem cell: Transport sugar
- Root hair cell: Take up water & minerals
Diffusion
Spreading out of particles from a high to a low concentration, down a concentration gradient.
Diffusion in cells
In: Carbon dioxide & urea
Out: Oxygen & glucose
Where does diffusion happen?
Cell membrane - larger the surface area the higher the rate of diffusion.
High temperatures = more kinetic energy and the steeper the concentration gradient, faster diffusion takes place
Osmosis
The diffusion of water molecules through a partially permeable membrane.
Active transport - requires energy
Moves substances against a concentration gradient (from low - high)
Surface area to volume ratio
A high surface area compared to volume means that an organism can exchange substances with its environment easily.
Calculate surface area
area = length x width
Calculate volume of a cube
volume = height x width x length
