Cell Ultrastructure Flashcards
(18 cards)
What are the functions of a nucleus?
- Control centre for protein synthesis (produces mRNA).
- Contains genetic material.
- Produces rRNA and ribosomes.
- Controls cell divisions.
What are the functions of a rough endoplasmic reticulum (RER)?
- Large SA for protein synthesis.
- Makes a pathway for transport of materials e.g. proteins.
What are the functions of a smooth endoplasmic reticulum (SER)?
- Synthesises, transports, stores lipids and carbohydrates.
- Contains lytic enzymes.
What are the functions of the golgi apparatus?
- Modifies proteins.
- Allows transportation of proteins in vesicles pinched off from golgi.
- Makes lysosomes.
What are the functions of a plasma membrane?
- Controls movement of materials in and out of cell.
- Contains receptors.
- Allows cells to attach forming tissues.
- Recognition sites for immune system.
What is the function of a chloroplast?
-The site of photosynthesis.
What is the function of the
mitochondria?
- The site of aerobic respiration.
- Where the krebs cycle takes place.
What is the function of the ribosome?
- Important in protein synthesis.
- Site of translation.
What is the function of lysosomes?
- Used to destroy foreign material inside and out of cell.
- Digests worn out organelles (autophagy).
- Breaks down cells after death (autolysis).
What are the structures of a nucleus?
- 10-20 micrometres.
- Nuclear envelope (controls what goes in and out of the cell).
- Nuclear pore (passage of things in and out).
- Nucleoplasm (like cytoplasm).
- Chromatin (uncoiled DNA and histone proteins).
- Nucleolus (makes ribosomal RNA and assembles ribosomes).
What is the structure of the rough endoplasmic reticulum?
- Enclosed flattened sacs continuous with nuclear membrane.
- Lots of ribosomes on the surface.
What is the structure of the smooth endoplasmic reticulum?
-Enclosed flattened sacs continuous with nuclear membrane.
What is the structure of the golgi apparatus?
- Has a stack of membranes that make flattened sacs called ‘cisternae’ and associated hollow vesicles.
- It has 2 faces = the cis (receiving or forming or entry) face and the trans (maturing or exit) face.
What is the structure of the plasma membrane?
- 45% proteins.
- 45% phospholipids.
- 10% cholesterol, glycolipids and glycoproteins.
What is the structure of the chloroplast?
- 2-10 micrometres.
- Chloroplast envelope (material entry and exit).
- Stroma (photosynthesis).
- Grana (photosynthesis).
- Starch grains (carb store).
What is the structure of the mitochondria?
- Double membrane (material entry and exit).
- Cristae (large SA for enzymes).
- Matrix (semi-rigid containing proteins, DNA, lipids, allowing them to make their own organelles e.g. ribosomes).
What is the structure of the ribosome?
- 80S (eukaryote) or 70S (prokaryote) type smaller than 80S.
- 2 subunits made from ribosomal RNA and proteins.
What is the structure of the lysosomes?
- Contains up to 50 enzymes.
- 1 micrometre in diameter.
