Eukaryote cells working together Flashcards
Chromosomes structure
Bound to histone proteins
Linear
What makes up the nucleus in a cell?
Holds chromatin, material which makes chromosomes
Nucleolus
Double membrane
Chromosomes function
Genetic material which encodes for specific proteins controles activities of cells by transcribing specific proteins
Nucleolus structure
Dark stained regions
Nucleolus function
Sites of ribosomes production by assembling ribosome subunits from ribosomal RNA
Nucleus double membrane
Known as nuclear envelope with pores so molecules can enter, specifically for DNA replication
Where are ribosomes found in a cell?
Found freely in the cytoplasm
Attached to rough endoplasmic reticulum
+ in the mitochondria or chloroplasts
Ribosomes structure
Large subunit (protein)
Small subunit (protein)
Ribosomal RNA
Not surrounded by a membrane
What is the function of ribosomes?
To synthesise proteins
What ribosomes are found in eukaryotes?
80s
2 types of endoplasmic reticulum
Rough ER
Smooth ER
Smooth endoplasmic reticulum vs rough endoplasmic reticulum
Rough is covered in ribosomes and involved in modifying proteins
Smooth is not covered in ribosomes and processes carbs and lipids
Rough endoplasmic reticulum structure
Cisternae (flattened vesicles) which contain enzymes
Lumen
Ribosomes pebbled on surface
Rough endoplasmic reticulum function
Ribosomes translate for proteins to be secreted from cell or make up the membrane proteins or enter lysosomes
And then folds + processes these proteins
Smooth endoplasmic reticulum structure
Cisternae and lumen
But no pebbled enzymes on surface
Smooth endoplasmic reticulum function
Produces and stores lipids and carbohydrates
Sends them to the Golgi to be transported to where needed
Golgi apparatus structure
Flattened vesicles (cisternae) with lumen
Golgi vesicles being produced
Golgi apparatus function
Modifies proteins and lipids before packaging them into Golgi vesicles
To be secreted
Form cell membrane
Enter lysosomes
Vesicles structure
Phospholipid membrane bound
Vesicles function
A sac which stores and transports proteins from ribosomes /ER to Golgi then secreted out the cell
How does secretion occur in a cell
Vesicles containing protein or lipids etc are fused with cell membrane to release
What are lysosomes?
Special type of vesicles
Lysosomes structure
A phospholipid bilayer membrane
Contains hydrolytic enzymes and digestive proteins
Lysosomes function
Forms vacuole around dead organelles to HYDROLYSE IT
Aids phagocytes in phagocytosis
Releases hydrolytic enzymes in programmed cell death
What is exocytosis?
The fusion of membrane bound vesicles and lysosomes with cell surface membrane to release enzymes/ proteins etc into extra cellular space
And incorporate new lipids/ proteins in membrane
Mitochondria structure
Double membrane folded into Cristae
Forming a matrix with enzymes
Mitochondrial loop of DNA and mitochondrial ribosomes
Mitochondria function
The site of aerobic respiration which contains enzymes needed for it in cristae
Site of resynthesis of ATP (phosphorylation) and hydrolysis of ATP with enzymes
What organelles do only plant cells contain?
A permanent vacuole
Cell wall with a middle lamella
Chloroplasts
Structure of the vacuole
Enclosed in a membrane (the tonoplast)
Contains cell sap inside (dissolved sugars, ions, amino acids and waste products)
What is the function of the vacuole?
Separates unwanted chemicals in cell by tonoplast membrane
Maintains water pressure in cell
Cell wall structure
Consists of cellulose forming microfibrils forming cellulose fibrils
Has middle lamella on outside composed of polysaccharides
Cell wall function
Offers structural support to cell when water enters via osmosis increasing hydrostatic pressure
Prevents bursting
Chloroplasts structure
Double membrane on outside
Membrane bound thylakoids containing chlorophyll stack to form granum connected by lamellae
Contains loop of dna + ribosomes
Starch granules
And stroma
Chloroplasts function
The site of photosynthesis due to thylakoids containing thylakoids which are stacked to form granum for efficient light absorption
Why do chloroplasts and mitochondria contain its own dna and ribosomes?
To synthesise it’s proteins needed for functions eg enzymes and to replicate when needed during interphase before cell division
Which organelles have a double membrane?
Nucleus
Chloroplasts
Mitochondria
Endosymbiosis
The idea that one organism will live inside another for mutual benefit
Eventually evolved to form mitochondria/chloroplasts in cells - explains dna inside them
Mitochondrial/chromosomal dna vs nucleus dna
Mitochondrial and chromosomes dna is a continuous loop not bound to proteins
In nucleus it is linear and bound to histone proteins
All types of eukaryote cells
Animal cells
Plant cells
Algae cells
Fungi cells
Algae cell difference
Similar shape + components of plant cells
But chloroplasts are different shapes to plant cells
Fungal cells differences
Cell walls made of chitin
Do not have chloroplasts because they don’t photosynthesis
