Cells

• All living things are made of cells.
• Cells can be either prokaryotic or eukaryotic. Eukaryotic cells are complex and include all animal and plant cells. Prokaryotic cells are smaller and simpler, e.g. bacteria.
• Eukaryotes are organisms that are made up of eukaryotic cells.
• A prokaryote is a prokaryotic cell. (A single-celled organism).
• The different parts of a cell are called subcellular structures.
• Most animal cells have a nucleus, cytoplasm, a cell membrane, mitochondria and ribosomes.
• The nucleus of a cell contains genetic material that controls the activities of the cell.
• The cytoplasm of a cell is a gel-like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reactions.
• The cell membrane of a cell holds the cell together and controls what goes in and out.
• The mitochondria of a cell is where most of the reactions for aerobic respiration take place. Respiration transfers energy that the cell needs to work.
• The ribosomes of a cell are where proteins are made.
• Plant cells usually have all the bits that animal cells have, plus a few extra things that include a rigid cell wall, a permanent vacuole and chloroplasts.
• The rigid cell wall in a plant cell is made of cellulose. It supports the cell and strengthens it.
• The permanent vacuole of a plant cell contains cell sap which is a weak solution of sugar and salts.
• The chloroplasts of a plant cell are where photosynthesis occurs which makes food for the plant. They contain a green substance called chlorophyll, which absorbs the light needed for photosynthesis.
• Bacteria are pro karyotes.
• Bacteria don’t have chloroplasts or mitochondria.
• Bacteria cells don’t have a ‘true‘ nucleus - instead they have a single circular strand of DNA that floats freely in the cytoplasm.
• Bacteria cells contain one or more small rings of DNA called plasmids.