Structure Of Eukaryotic Cells Flashcards
1
Q
List the organelles of eukaryotic cells
A
- cell-surface membrane
- nucleus (containing chromosomes, consisting of protein-bound, linear DNA, and one or more nucleoli, nuclear pores, nuclear envelope)
- mitochondria
- chloroplasts (in plants and algae)
- Golgi apparatus and Golgi vesicles
- lysosomes (a membrane-bound organelle that releases hydrolytic enzymes)
- ribosomes
- rough endoplasmic reticulum and smooth endoplasmic reticulum
- cell wall (in plants, algae and fungi)
- cell vacuole (in plants)
- cytoplasm
2
Q
Which organelles do animal cells have?
A
- cell-surface membrane
- nucleus (containing chromosomes, consisting of protein-bound, linear DNA, and one or more nucleoli)
- mitochondria
- Golgi apparatus and Golgi vesicles
- lysosomes (a membrane-bound organelle that releases hydrolytic enzymes)
- ribosomes
- rough endoplasmic reticulum and smooth endoplasmic reticulum
- cytoplasm
3
Q
Which organelles do plant cells have?
A
- cell-surface membrane
- nucleus (containing chromosomes, consisting of protein-bound, linear DNA, and one or more nucleoli)
- mitochondria
- chloroplasts (in plants and algae)
- Golgi apparatus and Golgi vesicles
- ribosomes
- rough endoplasmic reticulum and smooth endoplasmic reticulum
- cell wall (in plants, algae and fungi)
- cell vacuole (in plants)
- cytoplasm
4
Q
Describe the structure of the nucleus
A
- nuclear envelope: double membrane
- nuclear pores
- nucleoplasm: granular, jelly like material
- chromosomes: protein bound, linear DNA
- nucleolus: smaller sphere inside which is site of rRNA production and makes ribosomes
5
Q
Function of the nucleus
A
- contains genetic material for protein synthesis
6
Q
Structure of the rough endoplasmic reticulum
A
- folded membranes called cisternae
- have ribosomes on the cisternae
7
Q
Function of the rough endoplasmic reticulum
A
- protein synthesis
8
Q
Structure of smooth endoplasmic reticulum
A
- folded membranes called cisternae
9
Q
Function of the smooth endoplasmic reticulum
A
- synthesis and store lipids and carbohydrates
10
Q
Structure of Golgi apparatus and vesicles
A
- folded membranes making cisternae
- secretary vesicles pinch off from cisternae
11
Q
Function of Golgi apparatus and vesicles
A
- add carbohydrates to proteins to form glycoproteins
- produce secretory enzymes
- secrete carbohydrates
- transport, modify and store lipids
- form lysosomes
- molecules labelled with their destination
- finished products transported to cell surface in Golgi vesicles where they fuse with the membrane and the contents in released
12
Q
Structure of lysosomes
A
- bags of digestive enzymes
- can contain 50 different enzymes
13
Q
Function of lysosomes
A
- hydrolyse phagocytic cells
- completely break down dead cells (autolysis)
- exocytosis (release enzymes to outside of cell to destroy material)
- digest worn out organelles for reuse of materials
14
Q
Structure of mitochondria
A
- double membrane
- inner membrane called cristae
- fluid centre called mitochondrial matrix
- loop of mitochondria DNA
15
Q
Function of mitochondria
A
- site of aerobic respiration
- site of ATP production
- DNA to code for enzymes needed in respiration
16
Q
Structure of ribosomes
A
- Small mad up of two subunits of protein and rRNA
- 80s large ribosome found in eukaryotic cells
- 70s smaller ribosomes four in prokaryotic cells, mitochondria and chloroplasts
17
Q
Function of ribosomes
A
- site of protein synthesis
18
Q
Vacuole structure
A
- filled with fluid surrounded by a single membrane called a tonoplast
19
Q
Vacuole function
A
- make cells turgid and provide support
- temporary store of sugars and amino acids
- pigments may colour petals to attract pollinators
20
Q
Chloroplast structure
A
- surrounded by a double membrane
- contains thylakoids (folded membranes embedded with pigment)
- fluid filled stroma contains enzymes for photosynthesis
- found in plants
21
Q
Chloroplast function
A
- site of photosynthesis
22
Q
Cell wall structure
A
- in plant and fungi cells
- plants: made of microfibrils of the cellulose polymer
- fungi: made of chitin a nitrogen containing polysaccharide
23
Q
Cell wall function
A
- provide structural strength to cell
24
Q
Plasma membrane (cell surface membrane) structure
A
- found in all cells
- phospholipid bilayer (molecules embed within an attached on the outside; proteins, carbohydrates, cholesterol)
25
Q
Plasma membrane (cell surface membrane) function
A
- controls the entrance and exit of molecules
26
Q
Function of nuclear pores
A
- allows mRNA to leave the cell
27
Q
Function of nucleolus
A
- synthesises ribosomal RNA/ ribosomes
28
Q
Describe production of enzymes or cell surface glycoproteins in cells
A
- mitochondria supplies energy in the form of ATP and DNA coding for enzymes to made made is transcribed into mRNA templates
- amino acids pass from blood into cell via plasma membrane
- amino acids transported to ribosomes in rough endoplasmic reticulum by transfer RNA
- mRNA bonds to ribosomes initiating protein synthesis from amino acids and newly synthesised polypeptide enters the rough endoplasmic reticulum
- small, ribosome free, transfer vesicles carrying protons bud off from rough endoplasmic reticulum and fuse with the Golgi apparatus
- proteins may be modified and packaged as they move through the Golgi apparatus
- secretory vesicles (lysosomes) bud off Golgi apparatus an protons now in final structures (glycoproteins or enzymes)
- secretory vesicles move towards membrane (sometimes are stored)
- exocytosis; fusion of secretory vesicles with plasma membrane releases enzymes into digestive system or glycoproteins are now within cell surface membrane
29
Q
Give two examples of production of enzyme or cell surface glycoproteins
A
- Acinar cell of pancreas
- Liver cell with HDL recognition of glycoproteins
30
Q
How could a protein be modified?
A
- addition of carbohydrate groups
31
Q
Which enzymes could be released in exocytosis in production of enzymes?
A
- amylase, trypsin and lipase
