Cell Structure & Function Flashcards
What do vacuoles do?
Store materials and water in the animal cell
What are Golgi Bodies in Animal Cells and what do they do?
A series of stacked disk-shaped sacs.
Repackaging centre - stores modifies and packages proteins for transport
Produce lysosomes.
What is the function of a nuclear pore?
Allows materials into the nucleus, allows mRNA to leave.
What is the function of the nucleolus?
specialized are of chromatin which produces rRNA (ribosomal RNA) which is a component of ribosomes.
What do ribosomes do?
site of protein synthesis
Made up of ribosomal RNA and protein. - They are not enclosed in a membrane
Where are ribosomes located?
found attached to the surface of the rough endoplasmic reticulum or free floating in the cytoplasm
What does the smooth endoplasmic reticulum for?
It is where steroids hormones and some carbohydrates are synthesized.
Contains enzymes to detoxify drugs and alcohol (liver cells) and to synthesis lipids like steroid hormones.
There is NO ribosomes on it’s surface.
What is the mitochondrion for?
it is the site of many chemical reactions involved in energy (ATP) production
referred to as the powerhouse of the cell.
What do the free floating ribosomes do?
The site of protein synthesis
What does the nucleus do?
Control center of the cell - controls metabolic functioning of the cell & determines the cell’s characteristics
contains chromosomes coiled together as chromatin - DNA and proteins.
Contains DNA and RNA
What does the Lysosome do?
It contains the hydrolytic enzymes for intracellular digestion and cell destruction
- Attach to vacuoles and release hydrolytic enzymes to digest contents of the vacuole
- Suicide bags - release enzymes to destroy cell (Cell suicide)
Where do lysosomes come from in the cell?
They are pinched off from the golgi body
What is Chromatin?
The genetic material of the cell - Made of DNA and proteins
What is the function of the embedded proteins in the cell wall?
They are the carrier proteins
Form protein pores that allow small charges ions and large polar molecules to diffuse in/out of the cell.
Act as “pumps” actively transporting molecules in/out of the cell.
What does cholesterol do?
helps maintain structure and fluidity of the cell membrane
What are Glycoproteins and what do they do?
Carbohydrates attached to embedded proteins in the cell wall
Serve in cell recognition (antigens) and receptor (docking) sites on cell membrane
What are polysomes?
A group of ribosomes that translates (reads) a mRNA during protein synthesis.
What does it mean to detoxify?
inactivate potentially harmful drugs (including alcohol) by converting them to water-soluble compounds that can be eliminated from the body in urine.
What are vesicles?
small vacuoles that can be made at the ER, Golgi apparatus or from the folding of the cell membrane.
There are 2 types:
Transport vesicles
Secretory vesicles
What do transport vesicles do?
made at the ER and transport polypeptides to the Golgi Apparatus
What do Secretory vesicles do?
made at the golgi apparatus and transport product to cell membrane for secretion out of the cell by exocytosis
What are cilia?
tiny hairs that project from the cell membrane
used mainly as sweepers in the human body
found in the trachea and bronchi (airways) to sweep out debris before it can reach the lungs
also found in the fallopian tubes in females to sweep the egg towards the uterus
What is flagella?
a whip like tail used for motility (movement)
human sperm cell structures - the tail is also called a flagella
What is cytoskeleton?
a cellular scaffold or skeleton contained within the cytoplasm - made out of proteins
Maintains cell shape, protects the cell, enables cellular movement and plays important roles in intracellular transport
What is the function of a ribosome?
Produces polypeptides by reading mRNA in the process called translation.
Where can proteins end up?
secreted out
kept inside the cell
integrated into the cell membrane
What is the protein secretion pathway?
1 - Ribosomes make polypeptides
2 - Rough ER folds the polypeptides and acts to transport the polypeptides
3 - Transport vesicles carry the polypeptides to the Golgi Body
4 - Golgi further modifies the polypeptides (ex. Carbohydrate to protein)
5 - Secretory vesicles carry the protein to the cell membrane where it is excreted (in a process called exocytosis)
What is the problem with a small SA:Volume ratio?
If the SA:Volume ratio is too small then transport across the membrane can’t keep up.
If the SA:Volume ratio is too small what do the cells do?
Divide - Or in the case of certain organelles, fold their membrane.
What is passive transport?
It occurs when no energy (ATP) is required to get molecules in/out of the cell.
(Ex. Diffusion, Osmosis)
What is active transport?
It occurs when energy (ATP) is required to get molecules in/out of the cell.
What are some examples of active transport?
sodium/potassium pump, exocytosis and endocytosis
What is endocytosis?
A cellular process in which substances are brought into the cell.
It uses the cell membrane to form a vesicle
It requires energy
