AQA GCSE Science: Biology: Section 1: Cells and organisation
Terms in this set (82)
A measure of the ability to distinguish between two separate points that are very close together.
contains genetic information surrounded by the nuclear membrane.
The water-based gel where most of the chemical reactions of take place.
membrane around the contents of the cell that controls what moves in and out of the cell.
The site of aerobic cellular respiration in a cell.
The site of protein synthesis in a cell.
Single aquatic organisms (protista) that make their own food by photosynthesis.
The rigid structure around plant and algal cells. It is made of cellulose and strengthens the cell.
complex carbohydrate that makes up plant and algae cell walls and gives them strength.
where photosynthesis takes place.
green pigment contained in the chloroplasts.
Space in the cytoplasm filled with cell sap.
have a cell membrane, cytoplasm, and genetic material enclosed in a nucleus.
Single-celled prokaryotic organisms.
Cytoplasm surrounded by a cell membrane & cell wall that does not contain cellulose.
Genetic material is a DNA loop that is free in the cytoplasm, not enclosed by a nucleus.
Sometimes there are one or more rings of DNA called plasmids.
The non-living transport tissue in plants that transports water from the roots to the leaves.
The living transport tissue in plants that carries dissolved food (sugars) around the plant.
spreading out of the particles of any substance in a fluid, resulting in a net movement of particles from an area of higher concentration to an area of lower concentration (down a concentration gradient).
Partially Permeable Membrane
A membrane that allows only certain substances to pass through.
The diffusion of water through a partially permeable membrane from a dilute solution (higher concentration of water) to a concentrated solution (lower concentration of water) down the conc. gradient.
A solution that is the same concentration as the cell contents.
A solution that is more concentrated than the cell contents.
A solution that is less concentrated than the cell contents.
The pressure inside a plant cell exerted by the cell contents pressing on the cell wall.
The state of plant cells when so much water is lost from the cell by osmosis that the vacuole and cytoplasm shrink and the cell membrane pulls away from the cell wall.
The movement of substances from a dilute solution to a more concentrated solution against a concentration gradient, requiring energy from respiration.
Movement of air or water into and out of the gas exchange organ, for example lungs or gills.
Openings in the leaves of plants, particularly on the underside and opened and closed by guard cells, allowing gases to enter and exit the leaf.
one set of new chromosomes is pulled to each end of the cell forming two identical nuclei during cell division.
process where cells become specialised for a particular function.
Adult Stem Cells
Stem cells that are found in adults that can differentiate and form a limited number of cells.
The production of identical offspring by asexual reproduction.
The single new cell formed by the fusion of gametes in sexual reproduction.
Embryonic Stem Cells
Stem cells from an early embryo that can differentiate to form the specialised cells of the body.
A process where an embryo is produced that is genetically identical to the patient so the cells can be used in medical treatments.
A group of specialised cells with a similar structure and function.
An aggregation (collection) of different tissues working together to carry out specific functions.
A group of organs that work together to carry out specific functions and form organisms.
Organ system where food is digested and absorbed.
Biological catalysts, usually proteins.
Molecules that contain only carbon, hydrogen, and oxygen. They provide the energy for the metabolism and are found in foods such as rice, potatoes, and bread.
Small carbohydrate units, for example glucose.
Include fats and oils and are found in foods such as butter, olive oil, and crisps. They are made of carbon, hydrogen and oxygen.
Part of the structure of a lipid molecule.
Part of the structure of a lipid molecule.
Molecules that contain carbon, hydrogen, oxygen and nitrogen and are made of long chains of amino acids. They are used for building the cells and tissues of the body and to form enzymes.
Molecules made up of carbon, hydrogen, oxygen, and nitrogen that are the building blocks of proteins.
The breakdown of the molecular structure so it no longer functions.
A substance that speeds up the rate of another reaction but is not used up or changed itself.
The site on an enzyme where the reactants bind.
The sum of all the reactions taking place in a cell or the body of an organism.
Enzymes that speed up the breakdown of carbohydrates into simple sugars.
Enzyme that speeds up the digestion of starch into sugars.
Enzymes that speed up the breakdown of proteins into amino acids.
Enzymes that speed up the breakdown of lipids into fatty acids and glycerol.
Neutralises stomach acid to give a high pH for the enzymes from the pancreas and small intestine to work well. It is not an enzyme.
The clear yellow liquid part of the blood that carries dissolved substances and blood cells around the body.
Red Blood Cells
Biconcave cells that contain the red pigment haemoglobin and carry oxygen around the body in the blood.
White Blood Cells
Blood cells involved in the immune system of the body. They engulf pathogens and make antibodies and antitoxins.
Fragments of cells in the blood that play a vital role in the clotting mechanism of the blood.
The waste product formed by the breakdown of excess amino acids in the liver.
The red pigment that carries oxygen around the body in the red blood cells.
Blood vessels that carry blood away from the heart. They usually carry oxygenated blood and have a pulse.
Blood vessels that carry blood towards the heart. They usually carry deoxygenated blood and have valves to prevent the backflow of blood.
The smallest blood vessels. They run between individual cells and have a wall that is only one cell thick.
Double Circulatory System
The circulation of blood from the heart to the lungs is separate from the circulation of blood from the heart to the rest of the body.
The blood vessels that supply oxygenated blood to the heart muscle.
The upper chambers of the heart.
The large vein that brings deoxygenated blood from the body to the heart.
The large blood vessel that carries oxygenated blood from the lungs back to the left atrium of the heart.
Chambers of the heart that contract to force blood out of the heart.
The large blood vessel that takes deoxygenated blood from the right ventricle of the heart to the lungs.
The artery that leaves the heart from the left ventricle and carries oxygenated blood to the body.
A metal mesh placed in a blocked or partially blocked artery. They are used to open up the blood vessel by the inflation of a tiny balloon.
Drugs used to lower blood cholesterol levels and improve the balance of HDLs to LDLs in the blood.
The name given to cells that make up the epidermis or outer layer of an organism.
The upper layer of the Mesophyll tissue in plant leaves made up of closely packed cells that contain many chloroplasts for photosynthesis.
The lower layer of mesophyll tissue in plant leaves that contains some chloroplasts and many large air spaces to give a big surface area for the exchange of gases.
The movement of sugars from the leaves to the rest of the plant through the phloem.
Surround the stomata in the leaves of plants and control their opening and closing.
The loss of water vapour from the leaves of plants through the stomata when they are opened to allow gas exchange for photosynthesis. It involves evaporation from the surface of the cells and diffusion through the stomata.