Chapter 3: Carbon and the Molecular Diversity of Life

organic compound

A compound containing carbon (only exception is CO2).

macromolecules

Carbohydrates, nucleic acids, proteins are all _____________.

living things

Carbohydrates, nucleic acids, proteins, and lipids are the four main molecules of all _________ ________.

electron configuration

An atoms ___________ ____________ determines the kinds and number of bonds the atom will form with other atoms. This is the source of carbon's versatility.

4

Carbon has __ valence electrons. This makes carbon able to form large, complex molecules.

hydrocarbons

Organic molecules consisting of only carbon and hydrogen.

ATP

The primary energy-transferring molecule in the cell. Consists of an organic molecule called adenosine attached to a string of three phosphate groups.

polymer

A long molecule consisting of many monomers

monomer

Building block molecules

carbohydrates

Include sugars and the polymers of sugars

monosaccharides

The simplest carbohydrates are ____________, or simple sugars. Have molecular formulas that are usually multiples of CH2O.

polysaccharides

Carbohydrate macromolecules are ___________, polymers composed of many sugar building blocks. They have storage and structural roles.

glucose

Starch and cellulose are both polymers of __________ (Hint: The most common monosaccharide).

starch

A storage polysaccharide of plants, consisting entirely of glucose monomers. Stores ENERGY. Largely helical in shape. The glucose monomers are arranged in the α conformation.

glycogen

A storage polysaccharide in animals that mainly live in liver and muscle cells. Stores ENERGY. Largely helical in shape.

cellulose

A polysaccharide that is a major component of the tough wall of plant cells. Relatively straight in shape. The monomers are arranged in the β conformation.

beta

The ______ linkages in cellulose must pass completely through the digestive tract as insoluble fiber.

twice

Fats store _______ as much energy as glycogen.

chitin

A structural polysaccharide found in the exoskeleton of arthopods. Provides structural support for the cell walls of many fungi.

lipids

________ do not form true polymers. Have little or no affinity for water (hydrophobic). Consist mostly of hydrocarbons, which form nonpolar covalent bonds.

true

The most biologically important lipids are fats, phospholipids, and steroids. (T/F?)

fats

Constructed from two types of smaller molecules: Glycerol and fatty acids.

stores

Function of fats: _______ energy

glycerol

A three-carbon alcohol with a hydroxyl group attached to each carbon

fatty acid

Consists of a carboxyl group attached to a long carbon skeleton.

triacylglycerol

A fat is a ___________, where three fatty acids are joined to glycerol by and ester linkage.

saturated

___________ fatty acids that have the maximum number of hydrogen atoms possible and no double bonds.

unsaturated

___________ fatty acids that have one or more double bonds.

solid

Saturated fats are ________ at room temperature. Most animal fats are saturated.

liquid

Unsaturated fats or oils are _______ at room temperature. Plant and fish fats are usually unsaturated.

phospholipid

In a ____________, two fatty acids and a phosphate group are attached to a glycerol.

hydrophilic

The two fatty acid tails in a phospholipid are hydrophobic, but the phosphate group and its attachments form a ____________ head.

steroids

Lipids characterized by a carbon skeleton consisting of four fused rings.

cholesterol

An important steroid that is a component in animal cell membranes

stiff

Function of cholesterol: makes the cell membrane ________.

proteins

The structure determines the function of __________: Defense, storage, transport, cellular communication, movement, and structural support. Consist of one or more polypeptides.

enzymatic

Function of ___________ proteins: Selective acceleration of chemical reactions. Act as CATALYSTS

defensive

Function of __________ proteins: Protection against disease

storage

Function of __________ proteins: Storage of amino acids

transport

Function of _________ proteins: Transport of substances

hormonal

Function of _________ proteins: Coordination of an organism's activities

receptor

Function of _________ proteins: Response of cell to chemical stimuli

motor

Function of contractile and _______ proteins: Movement

structural

Function of _________ proteins: Support

polypeptides

Unbranched polymers built from the same set of 20 amino acids

amino acids

Organic molecules with carboxyl and amino groups. Differ in their properties due to differing side chains, called R groups. Proteins are polymers of these.

peptide bonds

Amino acids are linked by ________ ________.

primary

The _________ structure of a protein is its unique sequence of amino acids.

secondary

__________ structure, found in most proteins, consists of coils and folds in the polpeptide chain.

tertiary

_________ structure is determined by interactions among various side chains (R groups)

quarternary

_________ structure results from interactions between multiple polypeptide chains

unravel

Alterations in pH, salt concentration, temperature, a=or other environmental factors can cause a protein to _________.

denaturation

The loss of protein's native structure---->causes the protein to be biologically inactive

gene

The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a _______.

nucleotides

Genes are made of DNA, a nucleic acid made of monomers called ___________. Consists of a nitrogenous base, a pentose sugar, and one or more phosphate groups.

DNA

_______ provides directions for its own replication; directs synthesis of messenger RNA (mRNA) and, through mRNA, controls protein synthesis. A polymer made of nucleotides

polynucleotides

Nucleic acids are polymers called ____________.

nucleoside

The portion of a nucleotide without the phosphate group

fat synthesis

In ________ __________, glycerol and fatty acids combine to make fats plus water.

hydroxyl

In the reaction that builds a fat, ________ groups react with carboxyl groups

double bonds

Triglycerides vary with respect to the number of C atoms and _________ _________ in the tails.

hydrogenation

____________ removes double bonds, making fat less fluid.

carbonyl

DNA, proteins, and fats all contain _________ groups.

steroids

Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. An exception to this rule is _________.

peptide bonds

The secondary structure of a protein results from _______ _______.

hydrogen

α helix and the β pleated sheet structures of proteins are maintained by _________ bonds.

RNA

One of the functions of _______ is the synthesis of proteins

carbohydrates

What class of biological molecules consists of both small molecules and macromolecular polymers?

amylase

_________ breaks down starch.