Chapter 3 Organic molecules

Question 1

amino acid

Answer 1

A basic subunit of protein consisting of a short carbon skeleton that contains an amino group, a carboxylic acid group, and one of various side groups.

Question 2

biochemistry

Answer 2

The chemistry of living things, often called biological chemistry.

Question 3

carbohydrates

Answer 3

One class of organic molecules composed of carbon, hydrogen, and oxygen in a ratio of 1:2:1; the basic building block of carbohydrates is a simple sugar (monosaccharide).

Question 4

carbon skeleton

Answer 4

The central portion of an organic molecule composed of rings or chains of carbon atoms.

Question 5

carrier proteins

Answer 5

A category of proteins that pick up molecules at one place and transport them to another.

Question 6

chromosomes

Answer 6

Double stranded DNA molecules with attached protein (nucleoprotein) coiled into a short, compact unit.

Question 7

complex carbohydrates

Answer 7

Macromolecules composed of simple sugars combined by dehydration synthesis to form a polymer.

Question 8

denatured

Answer 8

Altered so that some of the protein’s original properties are diminished or eliminated.

Question 9

deoxyribonucleic acid (DNA)

Answer 9

A polymer of nucleotides that serves as genetic information. In noneukaryotic cells, it is a double-stranded loop and contains attached HU proteins. In eukaryotic cells, it is found in strands with attached histone proteins. When tightly coiled, the DNA and histone structure is known as a chromosome.

Question 10

double bond

Answer 10

A pair of covalent bonds formed between two atoms when they share two pairs of electrons.

Question 11

fats

Answer 11

A class of water-insoluble macro molecules composed of a glycerol and fatty acids

Question 12

fatty acid

Answer 12

One of the building blocks of a fat, composed of a long chain carbon skeleton with a carboxylic acid functional group.

Question 13

functional groups

Answer 13

Specific combinations of atoms attached to the carbon skeleton that determine specific chemical properties.

Question 14

genes

Answer 14

Any molecule usually segments of DNA, able to (1) replicate by directing the manufacture of copies of themselves; (2) mutate, or chemically change, and transmit these changes to future generations; (3) store information that determines the characteristics of cells and organisms; and (4) use this information to direct the synthesis of structural and regulatory proteins.

Question 15

glycerol

Answer 15

The anaerobic first stage of cellular respiration, consisting of the enzymatic breakdown of a sugar into two molecules of pyruvic acid.

Question 16

inorganic molecules

Answer 16

Molecules that do not contain carbon atoms in rings or chains.

Question 17

lipids

Answer 17

The phase of matter in which the molecules are strongly attracted to each other, but, because they have more energy and are farther apart than in a solid, they move past each other more freely.

Question 18

macromolecules

Answer 18

Very large molecules, many of which are composed of many smaller, similar monomers that are chemically bonded together.

Question 19

messenger RNA (mRNA)

Answer 19

A molecule composed of ribonucleotides that functions as a copy of the gene and is used in the cytoplasm of the cell during protein synthesis.

Question 20

nucleic acids

Answer 20

Complex molecules that store and transfer information within a cell. They are constructed of fundamental monomers known as nucleotides.

Question 21

nucleotides

Answer 21

Fundamental subunits of nucleic acid constructed of a phosphate group, a sugar, and an organic nitrogenous base.

Question 22

organic molecules

Answer 22

Complex molecules whose basic building blocks are carbon atoms in chains or rings.

Question 23

phospholipids

Answer 23

A class of water-insoluble molecules that resembles fats but contains a phosphate group (PO 4 ) in its structure.

Question 24

polymers

Answer 24

Combinations of many smaller, similar building blocks called monomers (mono = single) bonded together.

Question 25

polypeptide

Answer 25

A macromolecule composed of a specific sequence of amino acids.

Question 26

proteins

Answer 26

Macromolecules made up of one or more polypepides attached to each other by bonds.

Question 27

regulator proteins

Answer 27

Proteins that influence the activities that occur in an organism-for example, enzymes and some hormones.

Question 28

ribonucleic acid (RNA)

Answer 28

A polymer of nucleotides formed on the template surface of DNA by transcription; three forms have been identified: mRNA, rRNA, and tRNA.

Question 29

ribosomal RNA (rRNA)

Answer 29

A globular form of RNA; a part of ribosomes.

Question 30

saturated

Answer 30

A term used to describe the carbon skeleton of a fatty acid that contains no double bonds between carbons.

Question 31

steroids

Answer 31

One of the three kinds of lipid molecules characterized by their arrangement of interlocking rings of carbon.

Question 32

structural proteins

Answer 32

Proteins that are important for holding cells and organisms together , such as the proteins that make up the cell membrane, muscles, tendons, and blood

Question 33

transfer RNA (tRNA)

Answer 33

A molecule composed of ribonucleic acid. It is responsible for transporting a specific amino acid into a ribosome for assembly into a protein.

Question 34

true (neutral) fats

Answer 34

Important organic molecules composed of glycerol and fatty acids that are used to provide energy

Question 35

unsaturated

Answer 35

A term used to describe the carbon skeleton of a fatty acid containing carbons that are double-bonded to each other at one or more points.