Organelles of the cell

• DNA - contains chromosomes which are made up of DNA and protein (histones)
• Nuclear envelope - separates nucleus from the cell, double membrane, controls substances moving in and out of the nucleus 
• Nuclear pore - where the double membrane fuses, allows passage of substances (i.e mRNA, ribosomes) into the nucleus 
• Nucleoplasm - contains chromatin
• Nucleolus - site of formation of rRNA 
• Structure/size - spherical, 10-20 micrometers 

• Shape/size - cylindrical, 1-10 micrometers in size
• Cristae - folds in the inner membrane, increases the surface area for the attachment of enzymes involved in respiration
• Matrix - organic solution, containing lipids etc within cristae
• Ribosomes/DNA - allow the mitochondria to self-replicate and produce some of their own proteins
• Function - produce ATP for respiration - some reactions occur on the inner membrane, some in the matrix
• Surface area - large surface area:volume ratio. Reduces diffusion distance from the edge to the centre of the organelle

• Size - 70S in prokaryotes, 80S in eukaryotes
• Structure - Large subunit and small subunit
• Made from - rRNA and protein
• Function - protein synthesis, site of translation

• Structure - elaborate system of double membranes folded to form flattened sacs, interconnected and fluid-filled
• Nuclear envelope - continuous with it allows the transport of substances
• Smooth ER - lack ribosomes, associated with synthesis transporting lipids
• Rough ER - ribosomes on its surface, transports protein made there
• Present in cells making a lot of protein, e.g. glands

• Structure - similar to ER but more compact
• What happens? - vesicles containing polypeptides fuse with the Golgi body. Modifies and packages proteins and enzymes. Pinched off the other end 

Functions

• modifying and packaging enzymes and proteins,
• producing secretory vesicles containing enzymes and proteins
• producing glycoprotein,
• transporting and storing lipids,
• forming lysosomes

• Structure - two microtubules making hollow cylinders at 90 degree angles
• Location - just outside the nucleolus
• Role - organise the microtubules that make spindle for which chromosomes attach to in cell division
• Form a part of the paired structure that is a centrosome

• Role - supportive, contains cell sap, keeps the cell turgid which supports the plant
• Structure - fluid filled sac bound by a single membrane (the tonoplast)
• Cell sap - a mixture of glucose, amino acids, minerals and often mineral pigments

• Location - photosynthesising cells, especially mesophyll cells

Features:

• Envelope - the chloroplast envelope surrounds each chloroplast
• Stroma - fluid-filled, contains some products of photosynthesis
• Ribosomes/DNA - allow the organelle to self-replicate
• Thylakoid - flattened sacs containing photosynthetic pigment. When stacked, they're called 'granum' which can contain 2-200 thylakoids. Efficient arrangement providing a large surface area for trapping light energy

• Structure - largely made of cellulose. Held together in microfibrils, in the polysaccharide pectin 
• Transport - gaps between cellulose molecules made the wall fully permeable to minerals and dissolved ions. The apoplast pathway is the main way in which water crosses the root
• Communication - plasmodesmata pass through pits. This is the symplast network, very important in water transport
• Mechanical - laminated arrangement keeps the wall strong. Exerts pressure, allowing the cell to become turgid, giving the plant suppory