bio - cell structure and microscopes Flashcards
What type of cell are plant and animal cells?
Eukaryotic cells
- these make up eukaryotic organisms
What is the function of ribosomes?
Where proteins are made in the cell
What is the function of cell membrane?
Contols what enters and leaves the cell
What is the function of cytoplasm?
Where most of the chemical reaction take place.
What is the function of the nucleus?
Contains genetic material and controls the activities of the cell.
What is the function of mitochondria?
Where aerobic respiration happens
What is in a plant cell but not an animal cell?
cell wall, vacuole, chloroplast
What is the function of cell wall?
Adds strength and shape - made of cellulose
What is the function of chloroplast?
Contains chlorophyll and absorbs light needed for photosynthesis
What type of cell is a bacteria cell?
Prokaryotic
Which cell is bigger - prokaryotic or eukaryotic?
Eukaryotic
- the prokaryotic cells are MUCH smaller
What is the biggest difference between a prokaryotic cell and a eukaryotic cell?
In a prokaryotic cell, the genetic material is not enclosed in a nucleus.
Where is the DNA in a prokaryotic cell?
Floating around in the cytoplasm in long loops - plasmids.
Why have microscopy techniques developed over time?
Due to improving technology
Which microscope (electron or light) can produce images of higher magnification and resolution?
Electron microscope
What is magnification?
How much bigger an object appears compared to it’s actual size
What is resolution?
How detailed the image is
How do you calculate the Actual size?
Actual size = image size/magnification
What is 1mm in micrometres (um)
1000um
What is 1um in nanometres (nm)
1000nm
What is the method of the microscopy practical?
Sample method:
- place a tissue sample on a microscope slide
- add a few drops of a suitable stain
- place the slide on the microscope stage and focus on the cells using the lower power
- change to higher powered lens and refocus
- draw ant types of cells that can be seen
- add a magnification scale to the diagram
What are the hazards of the microscopy pratical?
- stains can be irritant
- lamps used as the light source can get hot
Why do you need a stain?
To make certain structures visible
Why lower the coverslip and press carefully?
To remove any bubbles
Why can you see the nucleus and cell wall but not the mitochondria?
They are too small.
How could we see the smaller structures (e.g. ribosomes)?
You would need to use an electron microscope.
