Organelles
- Created by: Poppy Ellis
- Created on: 13-09-17 18:26
Nucleus
Surrounds the nucleolus - surrounded by two memebranes (nuclear envelope).
7 - 10 micrometres
Largest organelle
nuclear envelope - pores allows molecules to pass through
Apart from red blood and phloem, controls the cell - houses genetic material.
.Parts - Nuclear envelope,nucleolus, nuclear pore.
Nucleolus
Creates ribonucleic acid and ribosomes
Travel out of nucleus - through nuclear pores - the cyptoplasm, involved in proteinsynthesis.
Contained within the nuclear envelope.
Rough Endoplasmic Rectilium
Found near the nucleus, flattened sacs (cisternae) - continuos with the nuclear envelope.
Studded with ribosomes - these are attatched to the cells membrane
Direct connection with the nuclear envelope allows molecules to pass through the membranes.
Transport proteins - Proteinsynthesis begins when mRNA moves from nucleus to a ribosome on the surface.
When proteins are complete - collect and RER pinch off a vesicle.
Smooth Endoplasmic Reticulum
Involved in making lipids and the production off steroids. Acts as a storage organelle.
Important in the creation and storage of lipids and steroids.
Double membrane of RER and SER forms small air sacs - (Cisternae).
Golgi apparatus
Both plant and animal cells. Another packaging organelle - takes large,complex molecules and packages them into vesicles - stores these or sends them out of the cell.
Also builds lysosomes - in a plant the golgi complex in the plant may also create complex sugars.
Package modified proteins - vesicles transport and are varied in size. Recieves proteins from the ER and modifies them - e.g. may add sugar to a molecule.
Lysosomes
Lysosmes - main role is to digest. Hold enzymes that were created in the cell.
A lysosome is a specialised vesicle that holds a variety of the enzymes. Enzymes are first created in the RER.
The proteins - packed in a vesicle and are sent to the golgi apparatus - golgi then does its final work and pinches off the particular vesicle.
This is a lysosome - it the floats in cyptoplasm until needed (single -membrane organelles).
Mitochondria
Biological process of the cell - Cellular respiration
Made of two membranes, outer covers the cell - the inner membrane folds over many times, and creates a layered structure - called a cristae (Fluid contained in the mitochondria - Matrix)
The folding = more surface area, chemical reactions take place in the inner membrane. Attatchment of enzymes. Can produce their own proteins.
Ribosomes and DNA floating within the matrix, Matrix filled with enxymes (Water and proteins)
Universal energy carrier (ATP) - provides energy for cellular activity.
Chloroplasts
Only in plant cells - food producers of the cell, work to convert light energy into sugars that can be used in the cell. Photosynthesis - depends on the chlorophyll of the cell.
Two membranes contain and protect the inner parts of the membrane,
Inner membrane surrounds the stroma and grana (stacks of thylakoids) - one thylakoid sac is a granum.
Photosyntesis reactions take place in the membranes and stroma of the chloroplasts.
The cell wall
It is rigid and make of cellulose fibres, running through a mixture of other polysaccharides.
The cell wall is fully permeable, unless a substance called lignin is deposited - makes the walls very strong and resistant to strain - but also completely impermeable.
Eukrayotic Cells
- Has a plasma membrane, cyptoplasm and ribosomes.
- Have a membrane bound nucleus.
- Numerous membrane bound organelles - including ER, golgi apparatus, and mitochondria.
Prokrayotic cells
- Unicellular organisms, lack organelles and membrane bound structures.
- DO NOT HAVE A NUCLEUS.
- Have a single chromosome.
- Have a circular, double stranded DNA located in an area of the cell called a nucleoid.
Vesicles
- Found in animal cells
- Various functions - common in secretory cells.
- Transport different substances - hydrophilic head and hydrophobic tail, regulates pressure and water in cells.
- Consists of fluid enclosed by a lipid - bi layer membrane.
Vacuole
- Function depends on cell - turgor pressure plants.
- Large vesicles, formed by smaller joining.
- Contain water - Many compounds in it
- Membrane bound - no specific shape.
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