Cells And organelles Flashcards
Describe the plasma (cell surface) membrane
Mainly made of lipids and proteins
Membrane is found on surface of animal cells and just inside the cell wall of plant cells
What is the function of the plasma (cell surface) membrane?
- Regulates the movement of substances into and out of the cell.
- has receptor molecules which allow it to respond to chemicals like hormones
Describe the cell wall
A rigid structure that surrounds plant cells.
Mainly made of cellulose (a carbohydrate)
What is the function of the cell wall
Supports plant cells
Describe the nucleus
A large organelle surrounded by a nuclear envelope (double membrane)
Contains chromatin (made from DNA and proteins)
Contains nucleolus
What is the function of the nucleus
Controls the cells activities (by controlling the transcription of DNA)
The pores allow substances (E.G.RNA) to move between the nucleus and the cytoplasm
The nucleolus makes ribosomes
Describe the lysosome
A round organelle surrounded by a membrane, with no clear internal structure
What is the function of the lysosome
Contains digestive enzymes
Can be used to digest invading cells or to break down worn out components of the cell
Describe the ribosome
A very small organelle that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum
Made up of proteins and RNA
not surrounded by a membrane
What is the function of ribosomes
Site where proteins are made
Describe the rough endoplasmic reticulum
A system of membranes enclosing a fluid filled space
Surface is filled with ribosomes
What is the function of the Rough Endoplasmic Reticulum
Folds and processes protein that have been made at the ribosomes
Describe the smooth endoplasmic reticulum
System of membrane enclosing a fluid filled space
No ribsomes
What is the function of the smooth endoplasmic reticulum
Synthesizes and processes lipids
Describe the vesicle
A small fluid filled sac in the cytoplasm surrounded by a membrane
What is the function of the vesicle
Transports substances in and out of the cell (via the plasma membrane)
Formed at the golgi or endoplasmic reticulum
While others are formed at the cell membrane
Describe the golgi apparatus
A group of fluid filled membrane bound
Flattened sacs
Seen at the edge of the cell
What is the function of the Golgi apparatus
Processes and packages new lipids and proteins
Makes lysosomes
Describe the mitochondrion
Oval shaped
Double membrane - inner is folded to form structures called cristae
Inside is the matrix which contains enzymes involved in respiration
What is the function of the mitochondrion
Site of aerobic respiration where ATP is producer
Found in large numbers in cells that are very active and require a lot of energy
Describe the chloroplast
Small flattened structure in plants
Surrounded by a double membrane
Has thylakoid membrane inside which are stacked up to form grana
Grabs are linked together lamellae
What is the function of the chloroplast
Site where photosynthesis takes place
Reactions happens in the grana or stroma
Describe the centriole
Small , hollow cylinders made of microtubules
Found in all animal but only some plant cells
What is the function of the centriole
Involved with the separation of chromosomes during cell division
Describe the cilia
Small hair like structures found on the surface membrane of some animal cells.
Ring of nine pairs of protein microtubules inside with 2 microtubules in the middle
What is the function of cilia
Microtubules allow the cilia to move
The movement is used by the cell to move substances along the cell surface
What organelles do plant cells have that animal cells do not
Chloroplast, Plasmodesma, Vacuole, Cell wall
State the function of the two organelles - mitochondria and Golgi apparatus
Mitochondria is the site of aerobic respiration
Golgi apparatus processes and packages proteins, lipids. It also makes lysosomes
How are organelles involved in protein production
Transcription of DNA to mRNA mRNA leaves the nucleus protein is made at ribosome on RER Protein enters RER transported by vesicles Vesicles fuse with Golgi apparatus Proteins are modified in Golgi Secretory Vesicles transport the protein Membrane of vesicle and membrane of cell fuses (exocytosis) Proteins are expelled
What are the four main functions of cytoskeleton
support the cell’s organelles
strengthen the cell and maintain its shape
responsible for movement of materials within the cell
Can cause the cell the move e.g. cilia
What is the difference between prokaryotes and eukaryotes
Prokaryotes are smaller DNA is circular whereas in eukaryotes DNA is linear No nucleus is prokaryotes Cell wall is made of polysaccharide Small ribosome No membrane bound organelles
What are the similarities and differences between laser confocal and light microscopy.
They both use light
Laser confocal can view objects at different depths, laser beams is used to scan a specimen which is tagged with a fluorescent dye.
what is the resolution and magnification for light microscope, TEM and SEM
Resolution for light - 0.2micrometers
SEM - 0.002 micrometers
TEM - 0.0002 micrometers
Magnification
Light - x1500
SEM - X500,000
TEM - 1,000,000
