1 - Cells and Organisation Flashcards
Eukaryotic Cells
Have a true nucleus (have a nucleus) and a cell membrane e.g.
Animal + Plant Cell
Prokaryotic cells
Have a false nucleus (no nucleus) Genetic material is usually kept freely in cytoplasm and they have no nuclear membrane e.g. Bacterial cells
Plasmid
Small ring of DNA usually found in Bacterial Cells
Cytoplasm
It Is a jelly like structure where most chemical reactions happen.
Nucleus
This controls what a cell does and contains all of the genetic information.
Mitochondria
This is where most reactions for aerobic respiration takes place and also cellular respiration (breaking nutrients and turning them into energy).
Ribosome
This is where protein synthesis happens.
Cell Wall
This gives protection and support to the cell e.g. Plant cell wall is made up of cellulose.
Permanent Vacuole
This contains cell sap which is a weak solution of sugar and salts.
Chloroplast
Contains chlorophyll which absorbs sunlight during photosynthesis.
Diffusion
The random movement of particles from an area of high concentration to an area of low concentration.
Xylem Cells
A transport tissue in plants.It carries water and dissolved mineral ions from the root up to the leaves.
Phloem cells
Is a transport tissue in plants.It carries dissolved food from the leaves around the plant.
Rate of Diffusion
How fast molecules will move from one place to another, the rate depends on the concentration gradient (how many particles there are) the temperature, surface area and the distance.
Osmosis
A special type of diffusion that only happens in water molecules it is when particles move from a low concentration (dilute solution) to a high concentration through a partially permeable membrane.
Magnification
Multiply the magnification of the eyepiece lens by the magnification of the objective lens e.g. Eyepiece = x4 and Objective = x10 then your overall magnification is: 4x10=x40
Active Transport
Allows cells to move substances from an area of low concentration to an area of high concentration.This movement is against the concentration gradient.
Resolution
Is the ability to distinguish between two separate points in an image and it is the resolving power of a microscope that affects how much detail it can show. E.g. A light microscope has a resolving power of about 200nm.
Order of Magnitude
Used to make approximate comparisons between numbers or objects.If one number is about 10 times bigger than another, it is an order of magnitude bigger.You show orders of magnitude using powers of 10.
E.g. A small animal cell has a length of around 10 micrometers.A large plant cell has a length of around 100 micrometers.
100
_________=10
10
So, a large plant cell is an order of magnitude or 10 to the power of 1 bigger than a small animal cell.
Nerve cell adaptations
1) Lots of dendrites
2) An axon that carries the nerve impulse from one place to another.
3) Nerve endings or Synapses pass the impulses to another cell or between a nerve cell and a muscle in the body using special transmitter chemicals.
Muscle cell adaptations
1) Special proteins that slide over each other making the fibres contract.
2) Contain many mitochondria to transfer the energy needed for the chemical reactions that take place as the cells contract and relax.
3) Store Glycogen, which can be broken down and used in cellular respiration by the mitochondria to transfer the energy needed for fibres to contract.
Sperm cell adaptations
1) A long tail whips from side to side to help move the sperm through water or the female reproductive system.
2) Middle section filled with mitochondria, transfers energy needed for tail to work.
3) The acrosome stores digestive enzymes for breaking down the outer layers of the egg.
4) Large nucleus contains genetic information that needs to be passed on.
Root hair cells adaptations
1) Increase surface area available for water to move into cell.
2) Large permanent Vacuole that speeds up of water by Osmosis from the soil across the root hair cell.
3) Many mitochondria that transfer energy needed for the active transport of mineral ions into the root hair cell.
Turgid
Cell is normal
Plasmolysis
A cell becomes plasmolysed when more water is lost via Osmosis, the vacuole and cytoplasm both shrink, and eventually the cell membrane pulls away from the cell wall.This is plasmolysis.
Lysis
Bursting an animal cell by osmosis.
Crenated
Shrinking an animal cell by osmosis