Cell Biology Flashcards
What is an active site?
The position on the surface if an enzyme molecule to which a specific substrate molecule can bind.
What do A, G, T, C and U represent?
They represent the names of bases of DNA (a,t,g,c) and RNA (a,g,c and U).
What is active transport?
The movement of a substance across a cell membrane against the concentration gradient from an area of low concentration to an area of high concentration.
What is aerobic respiration?
The release of energy from foods such as glucose using Oxygen; also produces water and Carbon dioxide.
What is ADP?
Adenosine diphosphate. When combined with phosphate makes ATP.
What is an amino acid?
The building block of proteins.
What is an antibody?
Y-shaped protein that is involved in the defence of animals.
Laboratory procedures designed to prevent contamination and keep sterile conditions are known as?
Aseptic techniques.
What is the name of the important chemical involved in transfer of energy in cells. It contains Adenosine and 3 inorganic phosphates.
ATP - Adenosine triphosphate.
What are base pairs?
Complementary bases found in DNA. A-T & G-C
What is carbon fixation?
A stage of photosynthesis which does not require light where carbon dioxide is combined with hydrogen to make carbohydrates (glucose/sugar).
What is the name of a substance that speeds up a chemical reaction but is left unaltered after the reaction?
A catalyst.
What is a cell culture?
The growth of cells in artificial conditions and in isolation of their original source.
Where do chromosomes become aligned during cell division (mitosis)?
The equator of a cell.
What are the features of the cell membrane?
It consists of a double layer of lipid molecules with associated proteins and controls the movements of substances into and out of the cell.
What organisms contain a cell wall?
Plants, fungi and some bacteria.
Cellulose is the main structural component of what?
Cell walls in plants.
What is the name of the green pigment in chloroplasts that absorbs light energy?
Chlorophyll.
What is a chloroplast?
An organelle containing Chlorophyll; it’s the site of photosynthesis.
What is a chromatid?
A copy of a chromosome visible during cell division (mitosis).
What is composed of DNA that codes for all characteristics in an organism, contains hereditary material and is found in the nucleus of a cell?
A chromosome.
What is the difference in concentration between substances inside and outside of a cell called?
The concentration gradient.
What is it called when an enzyme breaks a large molecule into smaller molecules?
Degradation
Definition of denaturation and what causes it?
Change to the shape and structure of an enzyme which stops it functioning. Usually happens due to high temperatures or extremes of pH
Definition of diffusion.
Passive movement of small molecules from an area of high concentration to an area of low concentration down the concentration gradient through a selectively permeable membrane.
What is it called when a cell contains 2 sets of chromosomes?
Diploid
What is DNA?
A chemical which forms chromosomes that carries genetic information of an organism.
What is the shape of DNA called?
Double stranded helix
Definition of an enzyme.
Protein produced by living cells that acts as a biological catalyst.
What is produced from pyruvate during the process of fermentation in yeast?
Ethanol.
What is fermentation?
A chemical pathway which occurs during respiration in the absence of oxygen.
What is it called when a plant cell contains less than the maximum volume of water it can hold?
Flaccid
What is the name of a region of a chromosome which contains genetic information that codes for a specific protein?
A gene
Definition of genetic code.
The sequence of bases on a DNA molecule which determines an organisms characteristics.
What is genetic engineering?
The artificial transfer of genetic information from one donor cell or organism to another cell or organism.
What is glycolysis and what is produced?
First stage of respiration (happens with or without oxygen). Glucose is broken down into pyruvate.
What is a hormone?
Protein released by an endocrine gland into the blood to act as a chemical messenger.
What is produced from pyruvate during fermentation in animal cells?
Lactic acid.
What is photolysis?
The first stage of photosynthesis producing Hydrogen and ATP required in the carbon fixation stage.
What is a variable called when in short supply limits the rate of a chemical reaction?
A limiting factor eg light intensity in photosynthesis.
What is the lock and key hypothesis?
The description of the shape of an enzymes active site must match the shape of a substrate molecule for a reaction to take place.
What is mRNA?
A single stranded substance that carries a complementary copy of genetic code from DNA (in the nucleus) to a ribosome (in the cytoplasm).
Where is the site of aerobic respiration?
In the mitochondria of a cell.
What is the process of cell division when a cell is split into 2 identical daughter cells.
Mitosis
What is the control centre of a cell that contains genetic information?
Nucleus
What is an optimum condition?
It is the best conditions for a reaction to take place.
Definition of osmosis.
The movement of water from an area of high concentration to an area of low concentration down the concentration gradient through a selectively permeable membrane.
What is the process by which plants produce food?
Photosynthesis
What is a plasmid?
A small circular molecule of DNA found in bacteria.
When a plant cell has lost and the vacuole and cytoplasm have shrunk away from the cell wall is known as?
Plasmolysed
What is the process by which a cell releases energy from food?
Respiration
What is the small organelle which acts as the site of protein synthesis?
Ribosome
What is RNA?
Similar to DNA but only one strand. mRNA used in protein synthesis.
What is selectively permeable?
Cell membrane that allows small soluble molecules to pass through but prevents larger molecules from doing so.
Enzymes are said to be what to substrates?
Specific to each substrate, one enzyme for each substrate
What is the function of spindle fibres?
Pull chromatids to the poles during cell division (mitosis).
When a plant contains the maximum volume of water it is said to be?
Turgid
What is a vector?
A vehicle used to transfer genetic material (gene) from one organism to another.
What is a unicellular fungus used in brewing and baking?
Yeast
What is a virus?
A very small microorganism that can be used as a vector in the transfer of genetic information.
