Starch, Glycogen, Cellulose and Plant Cell Structure

• polysaccharide
• found in many parts of a plant
• energy/food store
• made up of chains of alpha-glucose
• insoluble - no water into cell by osmosis, doesn't easily diffuse out of cells
• compact so lots can be stored in small space

• similar to strach but shorted chains and more highly branched
• carbohydate storage product of animals
• readily hydrolysed to alpha-glucose
• insoluble - no osmosis, doesn't easily diffuse out

• made up of beta-glucose
• straight, unbranched chains
• hydrgogen bonds between chains
• lots of hydrogen bonds strengthen it
• component of plant cell walls
• prevents the cell bursting from osmosis

This carries out photosynthesis and it's main features suit this function.

• long, thin cells to absorb sunlight
• numerous chloroplasts to collect maxiumum amount of light
• large vacuole that pushes the cytoplasm and chloroplasts to the edge of the cell.

• Chloroplast envelope - surrounds organelle and selective on what enters and leaves.
• Grana - stacks of thylakoids. These contain chlorophyll.
• Stroma - fluid-filled matrix.

Chloroplasts are adapted to their funtion of harvesting sunlight by:

• granal membranes provide large surface area for attached of chlorophyll, electron carriers and enzymes.
• fluid of the stroma possesses all the enzymes needed for photosynthesis.
• contain DNA and ribosomes so they can quickly manufacture proteins needed for photosynthesis.

• consist of polysaccharides (e.g. cellulose).
• thin layer (middle lamella) which marks the boundary between adjacent cell walls and cements adjacent cells together.

Functions

• provide mechanical strength to prevent it from bursting via osmosis.
• to allow water to pass along it.