Cells Flashcards
Describe exocytosis:
The secretion of substances from a cell
How does exocytosis take place?
It forms a new membrane by fusion of the vesicles within the plasma membrane, they increase surface area within the plasma membrane.
What is the golgi apparatus?
A series of flattened sacs (cisternae) with associated vesicles.
Where does the golgi apparatus receive proteins from?
The endoplasmic reticulum
What is the role of the golgi apparatus:
To label, sort and package proteins for export from the cell
Where is DNA contained?
In the nucleus, as chromosomes
What is the role of DNA?
To code for protein synthesis
The _____ membrane is a double membrane and has _____ which allow for exchange of substances in and out of the ______
- Nuclear membrane
- pores
- Nucleus
What is the largest cell organelle?
The nucleus
What structure contains DNA that codes for rRNA and produces ribosomes
Nucleolus
Where are lysosomes produced?
In the Golgi apparatus
How does the golgi apparatus modify proteins?
It can add:
- lipid
- carbohydrates
- co factors
- prosthetic groups
The golgi apparatus joins different polypeptides to form/produce proteins with a ______ structure:
Quaternary
Give 3 examples of eukaryotic cells
Fungi
Animal
Plant
Give 5 differences between a prokaryotic and eukaryotic cell
- Prokaryotic has not got membrane bound nucleus
- A prokaryotic cell has plasmids
- Prokaryotic cell has smaller ribosomes
- Prokaryotic has a peptidoglycan cell wall
- Prokaryotic has free DNA in the cytoplasm
What is the function of the nucleus?
The control centre of the cell
What cell does not have a cell wall?
An animal cell
What are 4 similarities between a prokaryotic cell and a plant cell?
- Cell wall
- DNA
- Cytoplasm
- Ribosomes
True or false. A prokaryotic cell has complex organelles
False
What is a prokaryotic cell wall made of
Glycoprotein known as peptidoglycan
What is cell fractionation?
Process to produce fractions of cellular components
Why is an isotonic buffer necessary?
Stops organelles expanding, bursting or shrinking
What is the main role of smooth endoplasmic reticulum?
Lipid synthesis
What is different about the structure of smooth endoplasmic reticulum and rough endoplasmic reticulum?
SER - no ribosomes
RER - ribosomes
What are ribosomes?
Tiny organelles found either in the cytoplasm or the RER
What does a ribosome consist of?
two sub-units
What are ribosomes main role?
Site of protein synthesis
What is the structure of mitochondria?
Double membrane bound
How is cristae formed?
Inner membrane folds inwards
What is the main role of mitochondria?
Site of aerobic respiration (energy production)
What is a cytosol?
Cytoplasm excluding organelles and nucleus
What is plasmodesmata?
narrow threads of cytoplasm - pass through adjacent cell walls - communication between plants
What do vacuoles store?
Ions and water
Why is a large vacuole important?
in the development of turgor for support
What are fungal cells walls made of?
Chitin
What does multinucleate mean?
More than one nucleus
What is nucleoplasm?
Cytoplasm found inside the nucleus - stores DNA
What is the function of the nuclear envelope?
Involved in letting things pass in and out of the nucleus
What are extrinsic proteins?
Attached peripherally to the bilayer
What are intrinsic proteins?
Embedded into one of the two layers
