B1 - Cell Structure and Transport Flashcards
What is the function of a cell wall?
The outer layer of a plant cell which strengthens and supports the cell
What is the function of the nucleus?
Control centre of the cell and contains all the DNA
What is the function of the cell membrane?
Controls what enters and leaves the cells
What is the function of ribosomes?
The site of protein synthesis
What is the function of the mitochondria?
The site of aerobic respiration (release of energy from food)
What is the function of the Chloroplasts?
Contains chlorophyll, site of photosynthesis
What is the function of the large permanent vacuole?
It stores cell sap
In which type of cell would you find a cell wall?
Plant cell only
In which type of cell would you find ribsomes?
Both animal and plant cells
Name 2 differences between plant cells and animal cells
Plant cells have a cell wall, a vacuole and chloroplasts whereas an animal cell does not.
How do you calculate the total magnification?
Total magnification = Eyepiece lens x objective lens
Define resolution
the ability of a microscope to distinguish how clear the details are of a specimen
Define magnification
how much bigger an image is made, compared to it’s actual size.
What microscope do you use for viewing small organelles like ribosomes?
An electron microscope
What type of DNA do prokaryotic cells have?
1 circular chromosome which is NOT enclosed by a nucleus
What type of DNA do eukaryotic cells have?
Lots of linear (straight) chromosomes which are enclosed by a nucleus
How do you calculate the magnification when using size?
. Size of image
Magnification = ————————
Real size of
Object
Give two advantages of using an electron microscope instead of a light microscope
It has higher magnification
It has higher resolution
What are examples of Eukaryotic cells?
Animal cells
Plant cells
What is an example of a prokaryotic cell?
Bacteria cells
What are the three factors that affect the rate of diffusion?
The concentration gradient
Temperature
Surface area
What does it mean if a cell membrane is partially permable?
Only some particles can diffuse through them
Why does the temperature affect the rate of diffusion?
Higher temperatures gives the particles more energy and make them move faster
Why does the surface area of the membrane affect the rate of diffusion?
Higher rate of diffusion as there is more area for the particles to pass
What is Diffusion?
The net movement of particles from an area of higher concentration, to an area of lower concentration
What does net movement mean?
The Overall movement
How does the concentration gradeint affect the rate of diffusion?
the larger the concentration gradient (a bigger difference in particles), the faster the rate of diffusion will be
What is Osmosis
The net movement of water molecules across a partially permable membrane from a region of higher water concentration to a region of lower water concentration
What are solutes?
Dissolved particles like sugar or salt