Bioscience Chapter 4

Terms in this set (86)

Four major classes of macromolecules:

carbohydrates, lipids, proteins, and nucleic acids

Three of the four macromolecules form chainlike molecules called:

The repeated units are small molecules called:

Monomers are connected by covalents bonds via:

condensation reaction or dehydration reaction

Condensation reaction or dehydration reactions are:

One monomer provides a hydroxyl groups and the other provides a hydrogen and together they form water

Hydrolysis reactions are:

the break down of monomers via water dividing the monomers into a hydroxyl group and a hydrogen

Carbohydrates are:

Monosaccharides are:

Monosaccharides generally have molecular formulas that are some multiple of:

Most names of sugars end in:

Monosaccharides have a _______ group and multiple _______ groups that allow them to be ________:

carbonyl; hydroxyl; soluble

Monosaccharides are also classified by the number of:

carbons in the backbone; "carbon backbone"

Six carbon sugars are _____, five carbon sugars are _____, and three carbon sugars are _____:

hexoses; pentoses; trioses

Monosaccharides form what in aqueous solutions:

chain of 2 monosaccharides

Two monosaccharides can join with a ____ to form disaccharides via _____:

glycosidic linkage; dehydration

Oligosaccharide:

short chain of monosaccharides (3-9)

Polysaccharides:

polymers of hundreds to thousands of glycosidic linkages

Function of polysaccharides:

energy storage macromolecule that is hydrolyzed as needed; serve as building materials for the cell or whole organism

energy storage in plants; composed entirely of glucose monomers

energy storage in animals

2 possible ring structures of glucose:

hydroxyl group attached to the number 1 carbon fixed above (beta glucose) or below (alpha glucose) in ring plane

strucutral carbohydrate in plants; major componenet of the tough wall of plant cells

important structural polysaccharide used in exoskeletons of insects, spiders, and crustaceans

exception among macromolecules because they do not form polymers

Feature of lipids:

they are hydrophobic becuase their structure is dominated by nonpolar covalent bonds

constructed from glycerol and fatty acids

three carbon skeleton with a hydroxyl group attached to each carbon

consists of carboxyl group (COOH) attached to a long carbon skeleton often 16 to 18 carbons long

Fats are combined by:

three fatty acids are joined to glycerol by an ester linkage creating a tricylglycerol or triglyceride

Triglycerides are stored in:

If there are no carbon-carbon double bonds then the molecule is:

saturated fatty acid

If there are one or more carbon-carbon double bonds and formed by the removal of hydrogen atoms from the carbon skeleton then the molecule is;

unsaturated fatty acid

Saturated fatty acids are ____ chains but unsaturated fatty acids have a ___ wherever there is a double bond:

The major function of fats is:

Fat also functions to:

cushion vital organs

A layer of fats can also function as:

have two fatty acids attached to glycerol and a phosphate group at the third position; hydrophilic head, hydrophobic tails

When phospholipids are added to water they self-assemble into ____ with the ____ pointing toward the center and the ____ on the outside:

aggregates; hydrophobic tails; hydrophilic heads

At the surface of a cell phospholipids are arranged as:

bilayer; major component of membranes

Steroids are lipids with a carbon skeleton consisting of:

four fused carbon rings

Different steroids are created by:

varying functional groups attached to the rings

Cholesterol is also the precursor from which:

all other steroids are synthesized (testocerone and estradiol)

lipids that have long chains of fatty acids and act as water repellent

Protein functions:

structural support, storage, transport of other substances, intercellular signaling, movement, and defense against foreign substances

All protein polymers are constructed form teh same set of:

amino acids called amino acids

Polymers of amino acids are called:

consist of four componenets attached to a central carbon, the alpha carbon; components are hydrogen atom, a carboxyl group, an amino group, and a variable R group or side chain

The variable R group is responsible for:

producing the 20 different amino acids

Three different types of R groups:

hydrophobic, hydrophilic, charged (ionized) at cellular pH

Amino acids are joined together when a ____ removes a ____ from the ____ of one amino acid and a ___ from the amino group of another:

dehydration reaction; hydroxyl group; carboxyl end; hydrogen

The resulting covalent bond in amino acids:

At one end of the amino acid chain is free amino group, ____, and at the other is an amino acid with a free carboxyl group, ____:

N-terminus; C-terminus

The repeated sequence (N-C-C) is the:

polypeptide backbone

Attached to a polypeptide backbone:

various R groups

A functional protein:

consists of one or more polypeptides that have been precisely twisted, folded, adn coiled into a unique shape

A protein's specific conformation determines:

Process of proteins:

amino acid --> polypeptide --> protein

Primary structure of protein:

its unique sequence of amino acids

Secondary structure of protein:

results from hydrogen bonds at regular interals along the polypeptide backbone; typical shapes that develop are coils (alpha helix) or folds (beta pleated sheets)

Tertiary structure of protein:

determined by a variety of interactions among R groups and between R groups and the polypeptide backbone; occur via hydrogen bonds, ionic bonds, and hydrophobic interactions

Disulfide bridge:

strong covalent bonds that form between teh sulfhydryl groups (SH) of proteins in tertiary structures

Quarternary structure of proteins:

results rom aggregation of two or more polypeptide subunits

folding of many proteins protected by it by shielding out bad influences

protein with lipid attached

protein with carbohydrate attached

loss of 3D structure of protein due to disruption of weak bonds (hydrogen bonds)

Denaturing agents:

heat, chagne in pH, chemicals

The amino acid sequence of a polypeptide is programmed by:

A gene consists of regions of DNA:

a polymer of nucleotides

There are two types of nucleic acids:

ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)

When a cell reproduces itself by dividing:

its DNA is copied and passed to the next generation of cells

Nucleic acids are polymers of monomers called:

Each nucleotide consists of three parts:

a nitrogen base, a pentose sugar, and a phosphate group

have a single six-membered ring

Three different pyrimidines:

cytosine (C), thymine (T), and uracil (U)

have a six-membered ring joined to a five-membered ring

The two purines are:

adenine (A) and guanine (G)

The pentose joined to the nitrogen base is ___ in nucleotides of RNA and ___ in DNA:

ribose; deoxyribose

Polynucleotides are synthesized by:

connecing the sugars of one nucleotide to the phosphate of the next with a phosphodiester link

DNA molecules have two polynucleotide strands that spiral around an imaginary axis to form:

Adenine alwasy pairs with ___ with DNA or ___ in RNA:

thymine; uracil

Guanine always pairs with:

DNA contains genes in:

Protein synthesis takes place at:

ribosomes in cytoplasm

RNA carries isntructions from:

nucleus to cytoplasm

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