Vocab Chapter 1

Question 1

Cell

Answer 1

The smallest structural and functional unit of which all living things are built

Question 2

Cell theory

Answer 2

States that all organisms are composed of cells (and their products), all cells come from pre-existing cells and the cell is the smallest living organisational unit

Question 3

cytoplasm

Answer 3

all the contents of the cell except the nucleus

Question 4

Plasma membrane

Answer 4

Phospholipid double layer that encloses the contents of a cell and controls the movement of substances into and out of the cell

Question 5

DNA

Answer 5

A nucleic acid made up of a sequence of deoxyribose sugars and bases (adenine, cytosine, guanine, and thymine) linked by phosphate bonds. it is the carrier of genetic information in all cellular organisms and most viruses; found in chromosomes (and mitochondria and chloroplasts)

Question 6

Organelle

Answer 6

Subcellular structure found in eukaryotic cells which are involved in specific functions of the cell

Question 7

Prokaryote

Answer 7

An organism with a simple cellular structure lacking most organelles

Question 8

Eukaryote

Answer 8

Organism composed of one or more cells that contain distinct membrane-bound nuclei and many organelles; includes protists, fungi, plants and animals

Question 9

Organic Compounds

Answer 9

any of the complex molecules containing carbon that occur in living organisms; for example, proteins, carbohydrates and lipids

Question 10

inorganic compound

Answer 10

all compounds other than organic compounds; for example, water, carbon dioxide, calcium carbonate (lime)

Question 11

Hydrophobic

Answer 11

molecules and compounds that repel water

Question 12

Hydrophilic

Answer 12

Polar ions and molecules that dissolve easily in water

Question 13

pH

Answer 13

A measure of acidity or alkalinity, measured on a scale of 0 (most acid) to 14 (most alkaline). One unit on a pH scale means a tenfold difference in acidity or alkalinity

Question 14

ATP

Answer 14

Adenosine triphosphate. Molecules of ATP provide energy for immediate use by the cell; produced during glycolysis and cellular respiration

Question 15

Biomacromolecules

Answer 15

Large organic molecules formed by joining together many smaller units (monomers) to form a chain or polymer, for example polysaccharides, nucleic acids and proteins

Question 16

Polymer

Answer 16

Large organic molecules, formed by joining together many smaller moleules (also known as macromolecules)

Question 17

Carbohydrate

Answer 17

Organic compound, such as sugars, starch and cellulose, that is made of carbon, hydrogen and oxygen, the hydrogen and oxygen are present in the same proportion to water (2:1)

Question 18

Protein

Answer 18

Functional molecule that is composed of one or more polypeptides, which are linear sequences of amino acids.

Question 19

Protein Structure

Answer 19

Four levels: primary (the linear sequence of amino acids, secondary (pleating or coiling of the polypeptide chain), tertiary (subsequent three dimensional folding of the polypeptide) and quarternary (aggregation of more than one polypeptide)

Question 20

Amino Acid

Answer 20

Compound that is the building block of polypeptides. The key chemical features are the presence of an amino (NH2) group anf a carboxyl (COOH) group at opposite ends of the molecule

Question 21

polypeptide

Answer 21

A protein consisting of a number of amino acids linked together by peptide bonds. an amino group is found at one end of a polypeptide, a carboxyl group at the other.

Question 22

nucleic acid

Answer 22

the genetic material of all organisms; molecule in which information is stored that determines features of an organism and controls cellular activities

Question 23

RNA

Answer 23

ribonucleic acid, Nucleic acid made up of a sequence of ribose sugars and bases (adenine, cytosine, guanine and uracil) linked by phosphate bonds; includes mRNA tRNA and rRNA

Question 24

nucleotide

Answer 24

A molecule consisting of a 5-carbon sugar (ribose or deoxyribose), a nitrogenous base (purine or pyrimidine) and a phosphate group; the main building blocks of nucleic acids

Question 25

gene

Answer 25

the unit of heredity; a sequence of nucleotides that encodes a protein, tRNA, mRNA or rRNA molecule (i.e. covers three RNA types

Question 26

Chromosome

Answer 26

Dark staining thread-like structure in the nucleus; composed of DNA and proteins and contains genetic information in the form of genes arranged in a linear order. Found in constant numbers in body cells of organisms of a particular species

Question 27

Lipid

Answer 27

‘Fatty’ organic compound including fats and oils which is composed mainly of carbon, hydrogen and oxygen. lipids have proportionally less oxygen than carbohydrates, and may contain other elements.

Question 28

Phospholipid

Answer 28

Fat-like substance, usually based on glycerol; phospholipids are essential components of cell membranes; are involved in the uptake of fats and fatty acids from the products of digestion

Question 29

omega-3 (or -6) fatty acid

Answer 29

Fatty acid with a double bond (and kink) between the third and fourth (or sixth and seventh) carbon from the omega end

Question 30

Phospholipid

Answer 30

fat-like substance, usually based on glycerol; phospholipids are sessential components of cell membranes; are involved in the uptake of fats and fatty acids from the product of digestion.

Question 31

fluid-mosaic model

Answer 31

in relation to cell membranes - fluid because of the lateral movement of lipid molecules and mosaic because of the irregular location of proteins in the membrane

Question 32

diffusion

Answer 32

passive movement of a solute from a region of higher concentration to a region of low concentration

Question 33

concentration gradient

Answer 33

difference in concentration of a solute between one region and another, for example across a membrane

Question 34

Osmosis

Answer 34

Passive diffusion of free molecules across a differentially permeable from a solution in which there are more free water molecules (a dilute solution) to a solution in which there are fewer free water molecules (a concentrated solution).

Question 35

facilitated diffusion

Answer 35

passive diffusion through selective protein channels in membranes

Question 36

active transport

Answer 36

movement of substances across membranes that requires the expenditure of energy; occurs through selective protein channels