[OLD] Cells - Cell structure: Organelles Flashcards
What is the nucleolus?
Dark staining region of nucleus
What is the nuclear envelope?
Double membrane around the nucleus.
What does the Golgi apparatus do?
Modifies proteins received from rER (e.g by adding carbohydrates to them to make glycoproteins) and packages them into vesicles for secretion.
What do lysosomes contain?
Digestive enzymes such as lysozymes to break down pathogens and old cells and organelles
What does the plasma membrane do?
Separates cell’s contents from outside environment and controls what enters and leaves the cell.
What are chloroplasts?
They contain chlorophyll, where photosynthesis takes place. They are in plant cells only.
What are centrioles?
Pairs of organelles that form spindle fibres to move chromosomes during nuclear division. In animal cells only.
What are cilia?
Hair-like projections used to move mucus and substances over cell surface.
What is the flagella used for?
Locomotion
What are flagella called in eukaryotes?
Unduilpodia
What are plasmodesmata?
Strands of cytoplasm that connect adjacent plant cells.
What does the cytoskeleton consist of?
Various protein molecules (microfilaments, intermediate filaments and microtubules)
What do the protein molecules that make up the cytoskeleton do?
Give the cell structure and provide pathways for the movement of vesicles.
6 steps of protein processing
1) proteins synthesised in ribosomes on rER
2) proteins move to Golgi apparatus in vesicles
3) Golgi modifies proteins and packages them into vesicles
4) vesicles containing modified protein are carried to cell surface membrane
5) vesicle fuses with cell surface membrane
6) modified proteins released from cell by exocytosis
What is compartmentalisation?
Internal membranes surround organelles and vesicles within the cell bringing about different environmental conditions within the same cell. This allows the conditions inside each of these organelles to be optimised to the function of that organelle (e.g perfect pH and ion concentrations inside the ribosome to make proteins, perfect pH and ion concentration inside sER to synthesise lipids)
Name a type of Golgi vesicle
Lysosomes
Function of nucleus
Controls cell activity
Stores organisms entire genetic information in DNA in the form of nuclear chromatin
Function of ribosomes
Synthesises proteins
Function of mitochondria
Site of aerobic respiration to produce ATP - providing energy for the cell to move, divide produce secretory products, and contract
Function of Golgi apparatus
Modifies proteins for export
Secretes enzymes and carbohydrates
Forms lysosomes
Function of Golgi vesicles
Transports proteins by fusing with the cell-surface membrane.
Function of lysosomes
Removes useless and dangerous material through autolysis, digestion, hydrolysis, and exocytosis.
Function of rough endoplasmic reticulum
Synthesises and transports proteins
Function of smooth endoplasmic reticulum
Synthesises, stores and transports lipids and carbohydrates.
Function of the cell membrane
Separates contents of cell from outside environment
Controls which chemicals enter and leave the cell
Function of the cell wall
Gives cell strength, rigidity and shape
Protective barrier
Allows water to pass along it
Function of the vacuole
Keeps cell rigid by maintaining pressure inside the cell (prevents plants wilting)
Stores nutrients and waste products
Helps increase cell size during growth
Colours petals
What are the 5 parts of the nucleus?
Nuclear envelope Nuclear pores Nucleoplasm Nucleolus Genetic material
What are nuclear pores and what is their function?
Channels in the nuclear envelope allowing the passage of large molecules out of the nucelus
Function of the nucleolus
Manufactures ribosomal RNA and assembles ribosomes
How does the nucleus store genetic material?
As DNA stored in chromosomes or nuclear chromatin
How many nuclear pores does a nucleus have?
Around 3000
What are the 3 parts of a mitochondria?
Double membrane
Cristae
Matrix
