- Largest organelle;
- Surrounded by nuclear envelope (composed of two membranes, seperated by fluid) with nuclear pores (allow relatively large molecules through);
- Nucleolus is densest part, and spherical.
- House nearly all genetic material
- Chromatin consists of DNA and proteins (and instructions for making more proteins)
- Nucleolus - creates ribosomes & RNA which go through the pores into the cytoplasm where they synthesise protein;
Rough & Smooth Endoplasmic Reticulum.
- Flattened membrane bound sacs (cisternae)
- Continuous with outer nuclear envelope
- Studded with Ribosomes
- Transports proteins synthesised by the attached ribosomes (for secretion or placement on the plasma membrane)
- Lipid synthesis
- Stack of membrane boud, flattened sacs;
- Transport vesicles can bud off from the end.
- Processes material as it passes through
- Recieves proteins from RER and modifies them - e.g. create gylcoproteins and hormones or haemoglobin;
- Packages modified proteins into vesicles so they can be transported
- Vesicles can then go to plasma membrane and 'exocytosis' their contents through fusing with plasma membrane.
- Spherical or sausage shaped;
- Double membraned (because they orignated from bacteria), inner membrane (cristae) is highly folded (increase surface area)
- Central part - matrix, contains enzymes for Krebs Cycle.
- Contains circular loop of DNA and tiny ribosomes
- Create ATP (Adenosine Triphosphate) during aerobic respiration on inner membrane
- Therefore provide energy for the rest of the cell's activities;
- ATP - universal energy carrier.
- Double membrane, 'chloroplast envelope'
- Inner membrane is continuous, with 'eleborarte network' of flattened membrane sacs (thylakoids).
- Thylakoids - look like pile of plates,
- Stack called a granum (pl. grana)
- Have chlorophyll on them
- Contain ribosomes, starch grains and circular loop DNA (also originated outside plants like mitochondria)
- Stroma contains enzymes for Calvin cycle
- Site of photosynthesis.
Exta info... *irregular white blob is often starch whilst black ones are likely are oil/lipids
- Spherical sacs
- Single membrane
- Use cytoskeleton move
- Contain (powerful) hydolytic enzymes
- The type that digest invading microorganisms or penetrate egg cell
- Break waste down into smaller simple compunds that can be recycled in the cell
***A Type Of Vesicles***
- Consists of two subunits
- Some bound to RER & others loose in cytoplasm.
- Cleft where mRNA runs (so they can translate the instructions)
- Protein synthesis
- Assembly line where mRNA is used to assemble proteins from amino acids
- Small tubes of protein fibres (microtubules);
- Triplets of microtubules form a ring;
- Pair next to nucleus in animal cells and some protocists at right angles.
- Form spindles which move chromosomes during nuclear division.
Cillia & Flagella
Cillia & Undulipodium
- 9+2 structure - 9 pairs of microtubules around periphery and one pair in the centre
- Longer and normally one per cell
- Smaller and lots of them covering speific surface of cell. No larger than 10micrometres
- Move fluid outside the cell
- Move the whole cell.
- Microtubules cylinders (c. 25nm diameter);
- Made of tubulin
- Supports cell structure
- Movement of organelles (comme vesicles) inside the cell using microtubule motors and ATP
- Movement of an mcroorganism through a liquid or waft liquid past cell.
+ Fun Fact - Undulipodium contain microtubules
- Made of cellulose fibres
- Primary layer: Random arrangement
- Secondary layer: Fibres are parallel to one another then next layers are perpendicular to the previous layer.
- Withstand water/turgor pressure (donc stop the cell from bursting because of the permanent vacuole)
- Support whole plant structure.
- Surrounded by tonoplast (membrane)
- Filled with water and solutes
- Large cell vacuoles maintain cell stability.
- Pushes cytoplasm against cell wall making it turgid. Opposing pressures.