Unit 1A Flashcards
Multicellular
Made of many cells
Nucleus
A structure inside cells which contains DNA. It controls the cell’s activities.
Cytoplasm
The site of chemical reactions in cells.
Cell membrane
Forms the boundary of the cell and controls what goes in and out.
Vacuole
A compartment inside plant cells that stores dissolves sugars and salts.
Chloroplast
A structure inside plants cells where photosynthesis occurs, producing sugar.
Cell wall
A supporting structure around the outside of plants cells, which helps them to keep their shape.
Specialised cell
A cell with a particular shape, that is adapted to perform a specialised function. eg. a nerve cell, muscle cell or sperm cell.
Tissue
A group of similar specialised cells that work together to carry out a particular function. eg. muscle cells are grouped together to form muscle tissue.
Organ
Organs are made of several types of tissue working together. eg leaf, small intestine
Micrometre
A unit for measuring cells. 1mm (millimetre) = 1000 micrometres
Graticule
A tiny scale placed into the eyepiece of a microscope. Used for measuring cells.
Zygote
A fertilised egg.
Mitosis
Cell division used to create identical copies of an original parent cell. Needed for growth and repair of damaged tissues.
Chromosomes
Structures inside the nucleus that appear before cell division. They are made of DNA.
Chromatids
The 2 identical copies of the original chromosome that make up a replicated (copied) chromosome.
Centromere
Holds the 2 chromatids together until it is split apart during mitosis as the chromatids separate.
Cancer
Body cells divide in an uncontrolled way to create a mass of cells called a tumour.
Agar plate
Petri dish filled with nutrient jelly (agar). Used for growing micro-organisms.
Sterile (aseptic) technique
All equipment, hands and work areas need to be cleaned with heat/disinfectant to prevent growth of unwanted micro-organisms.
Colony
A group of micro-organisms growing on an agar plate. Each colony can be seen as an individual dot.
DNA
A molecule found in the nucleus of cells. Contains the instructions for building protein molecules.
Proteins
Large molecules made of many amino acids joined together. Used to build cells and to keep them working.
Genetic code
Sequences of 4 letters - A,C,G and T which form part of the DNA molecule.
Gene
A length of DNA base sequence (genetic code) which is used to build a specific protein by getting the amino acids in the correct order.
Fertilisation
A sperm and egg (each containing 23 chromosomes in humans) join together at fertilisation to create a fertilised egg (zygote) with 46 chromosomes.
Other species have different numbers of chromosomes.
Genetic disease
Caused by a faulty gene creating a faulty protein that doesn’t work properly. eg. cystic fibrosis. Can be inherited.
Therapeutic
Used as a treatment.
Genetic engineering
A gene is moved from one organism to another, allowing the modified organism to produce a protein that it couldn’t make before.
Plasmid
A small ring of DNA extracted form bacteria. Can be easily modified by genetic engineering.
Diabetes
A disease where the patient is unable to make the hormone insulin and therefore can’t control their blood sugar.
Recombinant plasmid
A plasmid which has been altered by genetic engineering to contain a new gene.
GM organism
Genetically modified organism. Has been altered by genetic engineering to contain a new gene.
Stem cell
Unspecialised cell that is able to copy itself and differentiate into specialised body cells.
Tissue stem cell
Stem cells found in tissues throughout the body. Able to turn into a limited range of cell types. Used for growth and repair of the tissues where they are found.
Used in treatments such as bone marrow transplants.
Embryonic stem cells.
Embryos are made of a ball of embryonic stem cells, that are able to differentiate into all types of cells. They are controversial as embryos are destroyed when they are used.
Transfusion
Donated blood which is matched by blood type, is given to a patient who has lost a lot of blood.
Transplant
Donated organs are given to a patient to replace diseased or damaged organs.
Assumed consent
It is assumed that your organs can be used for transplants in the event of your death, unless you opt out.
Enzymes
Protein molecules that act as biological catalysts - they speed up chemical reactions in cells and allow them to happen at low temperatures. They can be re-used and are not used up in the reaction.
Enzyme specificity
Enzymes only work on one substrate, which is an exact fit.
Substrate
The substance that an enzyme works on. It is turned into a product.
Product
The molecule that is produced as a result of an enzyme catalysed reaction.
Amylase
Enzyme that breaks down starch into maltose.
Catalase
Enzyme that breaks down hydrogen peroxide into water and oxygen.
Degradation reaction
Another name for a breakdown reaction. Large molecules are turned into smaller ones.
Synthesis reaction
Another name for a build-up reaction. Small molecules are joined together to make larger ones.
Phosphorylase
Enzyme that builds up glucose-1-phosphate into starch.
Iodine
Used to test for the presence of starch. Turns from orange to blue/black.
Benedict’s reagent
Used to test for the presence of sugars. Turns from blue to orange.
Rennet
A mixture of enzymes found in the stomachs of calves. Used to curdle milk into curds which are skimmed off and pressed together to make cheese.
Biological washing powder
Washing powder that contains enzymes to break down the large molecules in stains into small ones so that they can be removed more easily.
Pectinase
An enzyme used to extract fruit juice from fruit pulp by breaking down the cell walls to release the juice.
DNA fingerprinting
Used to identify people from their unique DNA patterns - eg. suspects in a criminal investigation.
Biotechnology
The use of living organisms in industry eg. the use of enzymes in cheese making, biological detergents and contact lens cleaners, or the use of yeast in brewing and baking.
Insulin
Hormone needed to control blood sugar. Can be produced by genetic engineering for treating diabetes.
