B1 - cell structure and transport Flashcards
What are the 5 organelles in an animal cell
Nucleus, ribosomes, mitochondria, cell membrane, cytoplasm
What do ribosomes do
Protein synthesis to make proteins for enzymes
What do mitochondria do
Respiration to produce energy for the cell
What is an organelle
A subcellular structure with a specific function
What 3 extra organelles do plant cells have
Vacuole, cellulose cell wall, chloroplasts
What does the vacuole do
Chemical store that supports the cell (sap)
What does the nucleus do
Contains DNA and controls the cell
What does the cell membrane do
Controls what goes in and out of the cell
What does the cellulose cell wall do
Keeps the cell rigid and strong
What do chloroplasts do
Photosynthesis for glucose
What are the object and image in a microscope
The object is the real thing, the image is what you see down the microscope
What are magnification and resolution
Magnification is how many times bigger the image is than the object, resolution is the ability to distinguish details
What is the difference between light and electron microscopes
Light microscopes use light reflected and magnify it using convex lenses, electron microscopes shoot electrons at it and bend them with electromagnets to magnify the image
Pros of light microscopes
Cheaper, portable, can use live specimens, colour
Pros of electron microscopes
High resolution, high magnification, can be 2D or 3D
Why are cells small
Smaller things have a higher surface area to volume ratio so the cell can have more surface area for diffusion per unit of volume
What are the differences between eukaryotic cells and prokaryotic cells
Eukaryotic have a nucleus with a membrane, are bigger and more complex
Prokaryotic don’t have a nucleus but DNA is free moving in the cell, are smaller, always have a cell wall and can have flagella, pilli or slime capsules
What is diffusion
The net movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached
What is equilibrium
Where the concentrations are equal across the whole area
What is osmosis
The diffusion of water from an area of high water concentration to an area of low water concentration through a semi permeable membrane
What is a selectively permeable membrane
A membrane that only lets certain particles through, usually small particles like water
What is the difference between hypertonic, hypotonic and isotonic
Hypertonic - strong solution
Hypotonic - weak solution
Isotonic - equal concentration solution
Compared to surroundings
What is active transport
The movement of particles against the concentration gradient. It uses energy.
What will both types of cell do in a hypertonic solution
Animal cells will crenate because water diffuses out, plant cells get plasmalysed
What will both types of cell do in a hypotonic solution
Animal cells will burst because water diffuses in, plant cells will go turgid
