Ch. 2 - Cells

• Partially permeable membrane • Made up of proteins, carbohydrates and cholesterol • Helps in cell recognition • Allows for the transport of nutrients through diffusion, osmosis and active transport.

• Protects the cell • Strengthens and maintains structure • Made of cellulose in plant cells and chitin in fungi

• Jelly like substance that fills the cells • Organelles float in it • All chemical reactions take place in it

• Contains the solution which has all the nutrients • Also known as the cell sac • Larger in the plant cell

• Contains genetic material • Inside a double membrane • DNA from the nucleus converts into RNA and moves out via pores and meets ribosomes.

• Production of food for plants through photosynthesis • Captures sunlight using chlorophyll

• Creates energy via aerobic respiration • Complex internal structure

• Unicellular • Composed of Ribosomal RNA (rRNA) and proteins) • Sites for protein synthesis - does so by reading messenger RNA from the nucleus

• Has ribosomes • Protein synthesis and modification

• Does not have ribosomes • Synthesis of lipids • Stores calcium ions • Detoxifies the cell

• Helps in the packaging of proteins

• Helps in cell splitting

• Plant cells have a cell wall, animal cells don’t. • Plant cells are rectangular, animal cells irregular/round. • Chloroplasts in plants, absent in animals. • Large central vacuole in plants, small vacuoles in animals. • Centrioles in animals, absent in plants.

• Cell wall – always present (not made of cellulose); supports the cell and prevents bursting. • No nucleus – DNA is free in the cytoplasm; hence called prokaryotic cells. • DNA – usually a single circular chromosome • Plasmids – small extra circles of DNA, sometimes present. • No mitochondria or chloroplasts – unlike plant and animal cells. • Cell wall is made of peptidoglycan

Tissues are groups of similar cells that join and work together, performing a similar function.

Specialised cells are cells which have special features to carry as their specific functions.

• Large surface area for more absorption • Present in plant roots • NO CHLOROPLASTS

• Tall and thin • Maximum number of chloroplasts - maximising photosynthesis

• Carries Oxygen • Contains haemoglobin • No nucleus • No mitochondria • Biconcave and large surface area

• Male gamete which participates in reproduction • Carries genetic information • Enzymes in acrosome helps dissolve the jelly coat of egg cells. parts: head, midpiece, tail

• Presence of cilia • Present in tubes leading to lungs - to remove dirt and other pathogens of the body • Present in oviduct - to help the eggs move (provides extra assistance)

• Messages in the form of electrical impulses get passed from one neuron to another • Myelin sheath acts as an insulator

• Help in movement through contraction and relaxation • Requires a lot of mitochondria as they need energy