2.1 Cell Structure Flashcards
What is magnification?
How much bigger the image is that the specimen.
What is resolution?
The ability to clearly distinguish the individual parts of an object.
What is the resolution and magnification of a light microscope?
Resolution = 200nm, Magnification = 1500
What can you see using a laser scanning microscope?
Images at different depths. They use laser beams to scan a specimen usually tagged with a fluorescent light, which is focused through a pinhole. A detector is hooked up to a computer and a 3 D image is made.
What can you see using a transmission electron microscope?
Organelles. Electromagnets are used to focus a beam of electrons which is then transmitted through the specimen. Denser parts absorb more light so look darker on the image.
What can you see using a scanning electron microscope?
Cell surfaces. They scan a beam of electrons across the surface, which knock the electrons from the specimen which are gathered into a cathode Ray. A 3D image is produced.
What is the magnification and resolution of a transmission electron microscope?
Resolution = 0.2 nm Magnification = 1,000,000
What is the magnification and resolution of a scanning electron microscope?
Resolution = 2nm Magnification = 100,000
How do you use a light microscope?
- Select the lowest power objective lens 2. Use the coarse adjustment knob to bring the stage to just below the objective lens. 3. Move the stage down until it’s roughly in focus. 4. Use the fine adjustment knob until you have a clear image.
Why do you stain samples?
Some objects may be transparent so you can stain them. Some parts of the object take up more of the dye than others so the contrast makes different parts show up.
What is the function of the nucleus?
It is the control centre of the cell. It stores the genome and transmits genetic information that provides instructions for protein synthesis.
What is the function of the RER?
It is responsible for the synthesis of proteins, as it is covered in ribosomes.
What is the function of the SER?
It is responsible for the synthesis of lipid and hormones.
What is the function of the Golgi apparatus?
It is where proteins and packaged and modified.
What is the function of lysosomes?
They are filled with hydrolytic enzymes that ingest and digest broken or unused parts of the cell.
What is the function of chloroplasts?
They are the site of photosynthesis in plants.
What is the function of the mitochondria?
- Produce ATP (Adenosine triphosphate), a nucleotide
- ATP transports chemical energy within cells for metabolism. Every cell uses ATP for energy. It consists of a base (adenine) and three phosphate groups.
What is the function of the vacuole?
It is filled with cell sap to help support plants.
What is the function of centrioles?
centrioles are involved in spindle formation during mitosis.
What is the function of Cillia?
They move bacterial cells away from danger and towards food.
What is the function of the cytoskeleton?
Complex system of microtubules that form a kind of road that motor proteins transport things along.
How do you make and secrete a protein?
The protein is transcribed in the nucleus then translated in the RER. Vesicles are pinched off and moved to the Golgi where they are modified. Vesicles are pinched off and then fuse with the plasma membrane and are released.
What is a prokaryotic cell wall made from?
Peptidoglycan.
What are the differences between prokaryotic and eukaryotic cells?
prokaryotic cells do not have a nucleus or any membrane bound organelles. They have 70s ribosomes (smaller) and the DNA is naked, not wound round a histone protein.
