Unit 1

Eukaryotic cells are in the human body and plants

They have:

• A nucleus
• Functionally compartmentalised organelles

The Nucleus

• Contains the genome: Code that describes what protein factors to produce in the cell
• Surrounded by a double membrane- Nuclear envelope
• Biomolecules pass in and out of the nucleus by nuclear pores in the membrane

The Nucleolus

• Structure within the nucleus
• Region in the organelle dedicated to building ribosomes (protein builders)

Rough ER:

• A highly folded membranous structure with the cystolic face littered with ribosomes
• It is a folded double membrane extending from the nuclear envelope
• It is a site of protein synthesis

Smooth ER:

• Folded membranous extention of the nuclear envelope without ribosomes
• A site for triglyceride and steroid synthesis

• A large multimeric macromolecular protein: RNA complex
• Dedicated to protein synthesis
• Messenger RNA (a copy of the DNA gene) passes through the protein complex which scans the RNA and produces protein

• A double membranous, bacterium like organelle that has a highly folded inner membrane
• Mitochondria enable the cell to respire aerobially
• Uses the energy from the breakdown of food biomolecules in order to respire

Golgi Apparatus

• A folded membranous network that buds off from the endoplasmic reticulum
• Involved in protein processing and sorting- Biomolecular tags may be added to some proteins
• Proteins are sorted either for export from the cell or transport within the cell
• The proteins are released from the golgi apparatus in vesticles to be exported

Vesticles

• Membrane sacs that contain proteins destined for export from the cell

• A lipid bilayer that envelopes the cytoplasm
• It seperates the cell from the outside environment
• It regulates the influx and efflux of chemical species

• Complex bundle of cellulose biopolymer: beta-glucose chains
• They provide structural support and flexibility to the cell
• Only found in plant cells

• Photosynthetic centres in plant cells only
• Double membrane with a highly folded internal network of membranes- the thylakois space
• Rich in photosynthetic proteins- proteins which capture light and use it to drive the synthesis of carbohydrates

• A membrane sac of biomolecules
• Storage for nutrients and waste products
• Act similarly to lysosomes

• Collection of highly dynamic proteins that can assemble and disassemble enabling the cell to morph into different shapes
• It is involved in the transport of cellular cargo around the cell as the protein chains act like a highway

• Consists of the cytosol (an aqueous gel) and all the biomolecules and chemicals involved in cellular activity.
• The organelles are suspended within the cytosol

• Membrane sacs containing degradative enzymes
• Involved in digesting defective proteins that are no longer required