B1 cell structure and transport Flashcards
What’s a eukaryotic cell
Cells which have a nucleus
Subcelular structures found in a animal cell
Nucleus, cell membrane, cytoplasm, mitochondria, ribosome
Subcelular structures in a plant cell
Nucleus, cell wall, cell membrane, cytoplasm, chloroplast, ribosomes, vacuole, mitochondria
Function of a nucleus
Controls all cell activity and contains DNA
Function of cytoplasm
Where most chemical reactions take place
Function of mitochondria
Where respiration takes place and releases energy for cell to use (powerhouse)
Function of the cell membrane
Controls movement of substances in and out of a cell
Function of ribosomes
Where protein synthesis takes place
Function of cell wall
Supports the cell and is made from cellulose
Function of chloroplasts
Where photosynthesis takes place as has chlorophyll to trap the sunlight in
Function of vacuole
Filled with cell sap and keeps cell turgid (swollen and ridgid) to support plant
What’s a prokaryotic cell
There smaller and don’t have a nucleus there DNA is a free single loop
Subcelular structures in a bacteria cell
Plasmids, cell wall, cell membrane, genetic material, cytoplasm, slime capsule, flagella
Function of plasmids
Small rings of bacterial DNA
Function of Flagella
Tail like protein stand which allows bacteria cell to move
Equation for magnification
Magnification = image size / object size
What’s resolution
Ability to distinguish between 2 separate points, the higher the resolution the finer detail you are able to see.
The 3 ways of transport in and out of a cell
Diffusion, osmosis, active transport
What’s diffusion
Net movement of particles from a high to low concentration down a concentration gradient
Factors which effect diffusion
Temp, surface area, difference in concentration
What’s osmosis
Diffusion of water from a dilute to concentrated solution across a partially permeable membrane
What happens if a plant cell in placed in a concentrated solution
H2O will leave the cell causing the cytoplasm to shrink from the cell wall making the cell hypertonic
What happens if a plant cell in placed in a dilute solution
H2O will enter the cell keeping it turgid making it hypotonic
What’s active transport
Movement of substances from low to high concentration against the concentration gradient which requires energy from respiration
What is differentiation
Process where cells change to carry out specific functions they are then called specialised cells
Duration of cell differentiation
Animal cells can on differentiate in the early stages and later on cell division is restricted to repairing and replacing cells. Plant cells retain the ability to differentiate through life of plant
Subcelular structures of a nerve cell
Nucleus, axon, nerve endings, dendrites
Subcelular structures of a sperm cell
Tail, midpiece with mitochondria, acrosome, haploid nucleus
Subcelular structures of a Phloem tube
Sieve plates, companion cells
Use of acrosome for the sperm
Contains enzymes that help penetrate the egg
Use of haploid nucleus in a sperm cell
Haploid = half so contains half the DNA needed to make an embryo
How does having cells fused together in the muscle cell help
It forms muscle fibres that contract together to create a strong pulling force
The use of sieve plates in the phloem
Have holes which allow movement of dissolved sugar to be transported around the plant
The use of companion cells for the phloem
Phloem cells don’t have many internal structures so need support from other cells to keep them alive
Why do xylem vessels have dead cells fused together forming a hollow tube
It creates a single uninterrupted tube allowing water and minerals up the plant
Why do xylem vessels have thick walls with spirals of lignin
Lignin makes the walls woody therefore strong allowing the tube to hold the water pressure
Why do root hair cells have a large vacuole
It increases the rate of osmosis
How to prepare a stained slide of onion cells
Use a pipette to put a drop of water or iodine onto slide as a stain and to hydrate the cell. Peel a translucent layer of the onions eperdermal tissue and onto the slide. Place a cover slip on top trying to reducing air bubbles.
How to view your slide under the microscope
Place slide on stage and clip in. Turn on the light of the microscope. Looking through the eye piece on a low power objective lens use a combination of the course and fine adjustment knob until the image is in focus. You can use a higher power objective lens if magnification isn’t strong enough. Draw what you see labelling the diagram including a title and magnification.
How to prepare a stained slide of cheek cells
Use a pipette to put a drop of water onto a slide. Swab the inside of your mouth with a sterile cotton bud and rub it into the water on the slide to transfer the cells. Place a drop of methylene blue stain onto the cells and place a cover slip to seal trying to reduce air bubbles.
How to investigate the effect of a range of concentrations of salt and sugar on the mass of plant tissue
Cut five potato cylinders of the same diameter and length with no skin and blot with tissue before measuring the mass of each one. Place each chip into a different boiling tube and concentration of salt for 1 hour. Remove and blot with tissue and measure mass again. Calculate % change in mass = mass at end -start/mass at start x10
What’s a control variable
Variable which is always kept the same during an experiment
Whats a dependent variable
The variable being tested or measured during experiment
What’s a independent variable
The variable which is changed during an experiment
