2.7 identify the chemical elements present in carbohydrates, proteins and lipids (fats and oils)
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2.3 describe the functions of the nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplasts, ribosomes and vacuole
Part Function Nucleus Contains genetic material, which controls the activities of the cell Cytoplasm Most chemical processes take place here, controlled by enzymes Cell membrane Controls the movement of substances into and out of the cell Mitochondria Most energy is released by respiration here Ribosomes Protein synthesis happens here Extra parts of plant cells Part Function Cell wall Strengthens the cell Chloroplasts Contain chlorophyll, which absorbs light energy for photosynthesis Permanent vacuole Filled with cell sap to help keep the cell turgid -BBC Bitesize
2.2 describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplasts, ribosomes and vacuole
Animal cell →The nucleus is in the centre of the cell ↳surrounded by cytoplasm ↳around the outside is the cell membrane. Plant cell →The vacuole in the centre of the cell ↳surrounded by cytoplasm ↳within it is the nucleus and chloroplasts ↳surrounding this is the cell membrane ↳around that is the cell wall.
2.1 describe the levels of organisation in organisms: organelles, cells, tissues, organs and systems
organelles ↓ cells ↓ tissues ↓ organs ↓ organ systems
1.4 understand the term pathogen and know that pathogens may include fungi, bacteria, protoctists or viruses
Pathogen: a biological agent that causes disease or illness to its host. ↳may include fungi, bacteria, protoctists or viruses. Viruses: - not living - small particles , smaller than bacteria - parasitic and can reproduce only inside living cells - they infect every type of living organism - have a wide variety of shapes and sizes - they have no cellular structure but have a protein coat and contain one type of nucleic acid , either DNA or RNA. - examples include the tobacco mosaic virus that causes discolouring of the leaves of tobacco plants by preventing the formation of chloroplasts, the influenza virus that causes ‘flu’ and the HIV virus that causes AIDS.
1.3 describe the common features shown by prokaryotic organisms such as bacteria
Prokaryotes are unicellular organisms that consist of a single prokaryotic cell . Prokaryotic cells are simple cells that do not have a true nucleus or other cell organelles . Bacteria and Archaea are the two domains of life that are prokaryotes. Prokaryotes can be contrasted with eukaryotes (plants, animals, fungi, and protozoa). Bacteria: - microscopic single-celled organisms; they have a cell wall , cell membrane , cytoplasm and plasmids - they don't have a nucleus but contain a circular chromosome of DNA - some bacteria can carry out photosynthesis but most feed off other living or dead organisms . - examples include Lactobacillus bulgaricus, a rod-shaped bacterium used in the production of yoghurt from milk, and Pneumococcus, a spherical bacterium that acts as the pathogen causing pneumonia.
1.2 describe the common features shown by eukaryotic organisms: plants, animals, fungi and protoctists
Plants : - multicellular organisms - cells contain chloroplasts - are able to carry out photosynthesis - cells have cellulose cell walls - store carbohydrates as starch or sucrose - examples include: flowering plants, such as a cereal (eg. maize), and a herbaceous legume (eg. peas or beans). Animals: - multicellular organisms - cells do not contain chloroplasts - not able to carry out photosynthesis - no cell walls - store carbohydrate as glycogen - examples: mammals (eg. humans) and insects (eg. housefly and mosquito). Fungi: - not able to carry out photosynthesis - their body is usually organised into a mycelium made from thread-like structures called hyphae , which contain many nuclei - some examples are single-celled - their cells have walls made of chitin - they feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products ; this is known as saprotrophic nutrition - they store carbohydrate a
1.1 understand how living organisms share the following characteristics: • they require nutrition • they respire • they excrete their waste • they respond to their surroundings • they move • they control their internal conditions • they reproduce • they grow and develop.
All living organisms require the following characteristics in order to survive: Movement - organisms move toward things like water and food and they move away from things like predators. Respiration - organisms release energy from their food by the process respiration. Sensitivity - organisms respond to changes in their environment. Control - organisms can control their internal conditions. eg. water and temperature. Growth - all organisms grow and develop into their adult form. Reproduction - organisms have to produce offspring in order for their species to survive. Excretion - organisms have to excrete (remove) waste. eg carbon dioxide and urine. Nutrition - organisms need nutrients to provide them with energy and the raw materials for growth and repair. eg. proteins, carbohydrates, vitamins , minerals and fats.