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
Plasma membrane (cell surface membrane) function
- controls the entrance and exit of molecules
26
Function of nuclear pores
- allows mRNA to leave the cell
27
Function of nucleolus
- synthesises ribosomal RNA/ ribosomes
28
Describe production of enzymes or cell surface glycoproteins in cells
- 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
Give two examples of production of enzyme or cell surface glycoproteins
1. Acinar cell of pancreas
2. Liver cell with HDL recognition of glycoproteins
30
How could a protein be modified?
- addition of carbohydrate groups
31
Which enzymes could be released in exocytosis in production of enzymes?
- amylase, trypsin and lipase
