3.2.1 Cell Structure Flashcards
What are the inner folds of mitochondria called?
Cristae
What is the function of the Golgi Apparatus?
To process & package new proteins & lipids; makes lysosomes.
What is the function of a lysosome?
Contain enzymes- lysozymes used to digest broken/invaded cells.
What is a ribosome made of?
Proteins, RNA
What is the function of a ribosome?
Protein synthesis
Describe the difference between smooth & rough endoplasmic reticulum.
Smooth= no ribosomes
What is the function of the smooth ER?
Synthesises & processes lipids
What makes up the cell wall of plants & algae?
Cellulose
What is a tonoplast?
The membrane of a vacuole
Why would an epithelial cell in the small intestine need lots of mitochondria?
Respiration, to give energy needed for absorption of nutrients by active transport
What is a tissue?
A group of similar cells performing a similiar function e.g. epithelial cells form epithelial tissue
What is an organ?
A group of similar tissues working together e.g muscular, epithelial & glandular tissues form the stomach.
Describe the function of the nucleolus.
Makes ribosomes
Give 2 differences between plant & fungal cells.
Fungi= no chloroplasts & chitin cell wall not cellulose
List 3 differences between eukaryotic & prokaryotic cells.
Prokaryotic = no membrane bound organelles, no nucleus, smaller ribosomes, murein cell wall
What is a plasmid?
A loop of DNA NOT part of main chromosomal DNA e.g. genes for antibiotic resistance. Not in all bacterial cells.
Why might a bacterial cell have a slime capsule?
To give protection against the cells of the immune system, to stop too much water leaving the cell
Why do prokaryotes undergo Binary Fission?
They don’t have a nucleus (mitosis is division of a nucleus)
What replicates in Binary fission?
Chromosomal DNA replicates once- plasmids may replicate many times
What is the role of the attachment proteins of a virus?
To allow viruses to invade host cells, by using complemetary binding to receptors on host cells.
Briefly describe the steps of viral replication.
- Viruses attach to host cells using attachment proteins 2. Genetic material is released into host cell 3. Host cell machinery replicates viral DNA/RNA/proteins 4. Viruses assemble & replicate 5. Viruses leave host cell
Describe the term resolution.
Level of detail seen in an image- how close together 2 objects are to be seen as separate.
Describe the term magnification.
The number of times larger an image of an object is compared with the actual size.
Describe 2 differences between a light microscope & SEM.
SEM- higher resolution (3-10nm rather than 200nm), higher magnification (200,000 rather than 2000), uses electrons rather than light, can see surface of cells- 3D image
Write down the formula for magnification.
magnification = size of image/ size of real object
1mm = ? μm
1mm = 1000 μm
50 μm = ? cm
0.005 cm
1mm = ? nm
1mm = 1,000,000m
Use standard form to write the number 0.00002 mm
2 x 10-5
List 3 organelles you cannot view with a light microscope.
ribosomes, ER, lysosomes
Describe when you would use a TEM.
To view a thin specimen, high resolution to see small objects.