Chapter 1 - Cells Flashcards
Production and secretion of Insulin
Where it is the job of insulin and where is it made?
Answer:
Insulin is made in the pancreas and secreted into the bloodstream and this acts on the target (liver and muscle) cells.
Production and secretion of Insulin
What is the first step of this process?
Step 1:
mRna copy of gene for insulins made in the nuclesus (transcription).
Production and secretion of Insulin
What is the second step of this process?
Step 2:
mRNA leaves nucleus through nuclear pore.
Production and secretion of Insulin
What is the third step of this process?
Step 3:
mRNA attaches to a ribosome in the rough endosplamic reticulum. This reads the instruction to assemble the protein.
Production and secretion of Insulin
What is the fourth step of this process?
Step 4:
Insulin molecules is pinched off in vesicles and travels towards the golgi.
Production and secretion of Insulin
What is the fifth step of this process?
Step 5:
Vesicle fuses with golgi.
Production and secretion of Insulin
What is the sixth step of this process?
Step 6:
Golgi processes and packages this molecule of insulin.
Production and secretion of Insulin
What is the seventh step of this process?
Step 7:
Packaged insulins pinched in vessicles from the golgi and this moves towards the cell surface membrane.
Production and secretion of Insulin
What is the step 8:
Step 8:
Vesicle fuses with cell surface membrane.
Production and secretion of Insulin
What is the ninth step of this process?
Step 9:
Excosytosis- Cell surface membrane opens and releases the insulin into blood- Stream
Prokaryotic Cells:
What is the function of the cell wall?
This is made of murein/peptidogiycan unlinke eukaryotic cells made of cellulose.
Prokaryotic Cells:
What is the function of the cell surface membrane:
It controls what enters and leave the cell.
Prokaryotic Cells:
What is the function of the cytoplasm?
Contains cytosol, where enzymes and other solutes are dissolved + reaction occur.
Prokaryotic Cells
What is the function of the ribosomes?
Protein synthesis occurs, they are smaller about 70s.
Prokaryotic Cells
What is the function of the mesosome?
Highly infolded region of the cell membrane where respiration occurs.
Prokaryotic Cells
What is the function of the bacterial DNA?
The DNA is found in a nucleoid without a membrane seperating it from the rest of the cell. This DNA contains genes for bacterial proteins.
What is the differences between prokaryotic and eukaryotic cells?
Prokaryotic Cells
> No membrane bound organelles (golgi, ER)
Cell walls made of murein/peptidoglycan
Smaller ribosomes (70s)
Respiration takes place in mesosomes
Prokaryotic cells are much smaller (1-5micrometre)
Eukaryotic Cells
> Membrane bound organelles (ER, golgi, lysosomes)
Cell wall, made of cellulose
Bigger Ribosomes (20nm)
Respiration takes place in mitochondria
Eukaryotic cells are bigger (10-100micrometres)
Question: What the function of each feature of the prokaryotic cells? (capsule,flagella,pili, plasmids)
What is the bacterial DNA ?
Capsule: A slime outer layer that protects the prokaryotes from dehydration
Flagella - Allow bacteria to move
Pili-Enable one bacterium to attach to another bacterium and exchange plasmids
Plasmids- Small loops of DNA, contain genes for antibiotic resistance.
Bacterial DNA: naked DNA that isn’t wound around histone proteins but floats in the cytoplasm as a loop.
What is the function of lysosomes?
> Small bags made from the golgi aparratus
A membrane bound (has a membrane around it) Sac of Digestive enzymes (hydrolotic enzymes)
Digest worn parts of cells
What is the function of golgi apparatus?
> Proteins are modified by adding sugar,lipid or being folded into their 3D shape.
> The proteins are packaged into vesicles, these are pinched off and exported or stored.
Structure Of Nucleus (not function)
- Describe the structure of chromatin?
- Describe the structure of nucleolus?
- Describe the structure of nuclear envelope?
- Describe the structure of nuclear pore?
- Chromatin: Genetic material ; DNA wound histone proteins ; cells into chromosomes when the cells dividing.
- Nucleolus: Contains RNA ; doesnt have a membrane around it ; Ribosomes are made
- Nuclear envelope: Has a double membrane; seperates contents from the cell to the rest of the nucleus
- Nuclear Pore: enables mRNA to leave the nucleus ; substances such as steroid hormones from the cytoplasm can enter the nucleus from these pores.
Mitochondria Structure (not function)
- Describe the structure of the matrix.
- Describe the structure of cristae.
- State the size of a mitochondrion.
- Matrix (contains enzymes –> for aerobic respiration. ATP is made and energy released.)
- Cristae( inner membrane folded to create a large surface area to increase rate of respiration.)
- 0.5μm-10μm
What is the function the rough endoplasmic reticulum?
> This is rough because it contains ribosomes, which make protein.
This transport proteins to golgi.
Compare the two endoplasmic reticulums?
Rough Endoplasmic Reticulum >membranes containing cisternae >coated with ribosomes Function: >transports substances from one pair of the cell to another (intracellular transport) >assemble amino acids into proteins
Smooth Endoplasmic reticulum
>membranes containing cisternae
>no ribosomes
>lipidsyntheis
What is the golgi apparatus function?
> Proteins are modified here
>Proteins are packaged into vesicles and then stored in cells or released.
Describe the two steps in photosynthesis?
First Stage of photosyntheis happens in the grana
Second stage in stroma
What is the function of smooth endoplasmic reticulum?
No ribosomes
Synthesise lipids
Involved absorption,synthesis and transport of lipids.
