Bio 1 Chapter 5 the structure and function of large biological molecules

what are 4 classes of biological molecules all living things are made up of?

carbohydrates, lipids, nucleic acids and proteins

within cells, small organic molecules are joined together to form?

larger molecules

what are macromolecules?

large molecules composed of thousands of covalently connected atoms

molecular structure and function are?

inseparable

what is a polymer?

a long molecule consisting of many similar building blocks

These small building block molecules are called?

monomers

which 3 of the 4 classes of life’s organic molecules are polymers?

carbohydrates, proteins, nucleic acids

what occurs when two monomers bond together through the loss of a water molecule

a condensation reaction or dehydration synthesis

what are macromolecules that speed up the dehydration process?

enzymes

polymers are disassembled to monomers by ___ which is a reaction that is essentially the reverse of the dehydration reaction

hydrolysis

(B)

(b) hydrolysis of a polymer (peep photo)

each cell has thousands of different kinds of

macromolecules

macromolecules vary among cells of an?

organism, vary more within a species, and vary even more between species

an immense variety of polymers can be built from?

a small set of monomers

COH include?

sugars and the polymers of sugars

the simple COH are?

monosaccharides, or single sugars

COH macormolecules are ___ , polymers composed of many sugar building blocks

polysaccharides

monosaccharides have __

molecular formules that are usually multiples of CH2O

what is the most common monosaccharide?

Glucose (C6H12O6)

how are monosaccharides classified by?

• the location of the carbonyl group (as aldose or ketose )

• the number of carbons in the carbon skeleton

though often drawn as linear skeletons, in aqueous solutions many __

sugars form rings

monosaccharides serve as a ?

major fuel for cells and as raw material for building molecules

a disaccharide is formed when a

dehydration reaction joins 2 monosaccharides

the covalent bond is called a

glycosidic linkage

polysaccharides are the

polymers of sugars, have storage and structural roles

the structure and function of a polysaccharide are

determined by its sugar monomers and the positions of glycosidic linkages

what is starch?

a storage polysaccharide of plants consists entirely of glucose monomers

plants store surplus starch as

grunles wihtin chloroplasts and other plastids

what is glycogen?

a storage polysaccharide in animals

humans and other vertebrates do what?

store glycogen mainly in liver and muscle cells

the polysaccharide ___ is a major component of the tough wall of plant cells

cellulose

like starch, cellulose is a?

polymer of glucose, but the glycosidic linkages differ

the difference of structural polysaccharides is based on

two ring forms for glucose: alpha and beta

polymers with alpha glucose are

helical

polymers with beta glucose are

straight

in straight structures,

H atoms on one strand can bond with OH groups on other strands

parallel cellulose molecules held together this way are grouped into

microfibrils which form strong building materials for plants

enzymes that digest starch by

hydrolyzing alpha linkages cant hydrolyze beta linkages in cellulose

cellulose in human food passes through the

digestive tract as insoluble fiber

some microbes use

enzymes to digest cellulose

many herbivores from cows to termites have

symbiotic relationships with these microbes

what is chitin

another structural polysaccharide is found in teh exoskeleton of arthropods / also provides structural support for the cell walls of many fungi

lipids are the one classs of large biological molecules that

do not form polymers

the unifying feature of lipids is having little or

no affinity for water

lipids are hydrophobic because

they consist mostly of hydrocarbons, which form nonpolar covalent bonds

the most biologically important lipids are

fats, phospholipids and steroids

fats are

constructed from 2 types of smaller molecules, glycerol and fatty acids

what is glycerol

a 3 carbon alcohol with a hydroxyl group attached to each carbon

what is a fatty acid

consists of a carboxyl group attached to a long carbon skeleton

fats separate from water because

water molecules form hydrogen bonds with each other and exclude the fats

in a fat, 3 fatty acids are joined to

glycerol by an ester linkage, creating a triacylglycerol, or triglyceride

fatty acids vary in

length (number of carbons) and in the number and locations of double bonds

saturated fatty acids have the

maximum number of hydrogen atoms possible and no double bonds

unsaturated fatty acids have

one or more double bonds

fats made from saturated fatty acids are called

saturated fats and are solid at room temp.

most animal fats are

saturated

fats made from unsatirated fatty acids are called

unsaturated fats or oils and are liquid at room temp

plant fats and fish fats are

usually unsaturated

a diet rich in saturated fats may contribute to __ through plaque deposits

cardiovascular disease

__ is the process of converting unsaturated fats to saturated fats by adding hydrogen

hydrogenation

hydrogenation vegetable oils also creates

unsaturated fats with trans double bonds

these trans fats may __ than saturated fats to cardiovascular disease

contribute more

the major function of fats is

energy storage

humans and other mammals store their fat in

adipose cells

adipose tissue also cushions

vital organ and insulates the body

in a phospholipid,

2 fatty acid and a phosphate group are attached to glycerol

the 2 fatty acid tails are hydrophobic, but the

phosphate group and its attachments form a hydrophilic head

when phospholipids are added to water they

self assemble into a bilayer, with the hydrophobic tails pointing toward the interior

what are steroids

are lipids characterized by a carbon skeleton consisting of 4 fused rings

what is cholesterol

an important steroid, is a component in animal cell membranes

although cholesterol is essnetial in

animals, high levels in the blood may contribute to cardiovascular disease

portein account for more than

50% of the dry mass of most cells

protein functions include

structural support, storage, transport cellular communications, movement and defense against foreign substances

what are enzymes

• a type of protein that acts as a catalyst to speed up chemical reactions

• can perform their functions repeatedly functioning as workhorses that carry out the processes of life

polypeptides are

polymers built from the same set of 20 amino acids

a protein consists of

one or more polypeptides

what are amino acids

• are organic molecules with carboxyl and amino groups

• differ in their properties due to differing side chains called R groups

amino acids are linked by

peptide bonds

a polypeptide is a polymer of

amino acids

polypeptides range in length from a few to

more than a thousand monomers

each polypeptide has a

unique linear sequence of amino acids

a functional protein consists of

one or more polypeptides twisted, folded, and coiled into a unique shape

the sequence of amino acids detemrines a

proteins 3 dimensioanl structure

a proteins structure determine its

function

the primary structure of a protein is its

unique sequence of amino acids

secondary structure (found in most proteins) consists of

coils and folds in the polypeptide chain

tetrtiary structure is determined by

interactions among various side chains (R groups)

quaternary structure results when a

protein consists of multiple polypeptide chains

primary structure is the

• sequence of amino acids in a protein, is like the order of letters ina long word

• primary structure is determined by inherited genetic information

the coils and folds of ___ result from hydrogen bonds between repeating constituents of the polypeptide backbone

secondary structure

typical secondary structures area coil called

an helix (alpha sign) and a folded structure called a pleated sheet (beta sign)

__ is determined by interactions between R groups, rather than interactions between backbone constituents

tertiary structure

these interactions between R groups include hydrogen bonds, ionic bonds, __, and van der Waals interaction

hydrophobic interactions

strong covalent bonds called __ may reinforce the proteins structure

disulfide bridges

results when 2 or more polypeptide chains form one macromolecule

quaternary structure

collagen is a fibrous protein consisting of

3 polypeptides coiled like a rope

hemoglobin is a globular protein consisting of

4 polypeptides: 2 alpha and 2 beta chains

what is sickle cell disease

• an inherited blood disorder results from a single amino acid substitution in the protein hemoglobin

• a slight change in primary structure in can affect a proteins structure and ability to function

in addition to primary structure, physical and chemical conditions can

affect structure

alterations in pH, salt concentration, temp., or other environmental factors can

cause a protein to unravel