Biology Chapter 3

Carbon skeletons vary in LENGTH. Skeletons may be BRANCHED or UNBRANCHED Skeletons may have DOUBLE BONDS Skeletons may be arranged in RINGS

It consists of an amino group and a carboxyl group.

link monomers to form a polymer ... removing a water molecule

dehydration ... a hydroxyl group

possibly glucose or fructose

1. fructose

3. grapes

Maltose

Hydrophiliac

Both are important components of cell membranes.

people who suffer from muscle-debilitating diseases

When the body uses proteins as fuel, it is breaking down substances vital to its structure and essential functions.

Secondary structure involves hydrogen bonding between atoms of the polypeptide backbone.

uracil pairs with adenine and cytosine pairs with guanine

DNA consists of a triple helix structure

deoxyribose sugars, which are bonded to a phosphate group and a nitrogenous base

Although most mammals, including humans, are not able to digest the milk sugar, lactose, after infancy, the ancestors of northern and western Europeans relied on dairy products as an important part of their food supply. When other food sources were in low supply, mutations that allowed the expression of the enzyme lactase to persist past childhood conveyed an advantage to adults who were able to include dairy products in their diet.

2. C3H8

4. CH4 Compounds containing carbon are said to be organic.

Carbon

each carbon atom can form up to four covalent bonds with a wide variety of bond angles

carboxyl

1. R-NH2

alcohol ... amino

all are hydrophilic and increase the organic compound's water solubility

all share the same functional group, a hydroxyl

-COO - When an oxygen atom is double-bonded to a carbon atom that is also bonded to a hydroxyl group, the entire assembly is called a carboxyl group (-COOH).

acid; amino. A carboxyl group has acidic properties because it can donate a proton (hydrogen ion) to a solution. The amino group acts as a base because it can pick up or accept a protein (H) from a solution

dehydration reaction Monomers are linked together with the removal of a water molecule by dehydration reaction.

a polymer breaks up to form monomers ... consumed The meaning of "hydrolysis" is to break with water.

proteins, nucleic acids, carbohydrates, and lipids

The reaction hydrolyzes the sugar.

1. C60H100O50 Carbohydrates have molecular formulas that are multiples of CH2O.

as fuel Simple sugar molecules are a major fuel for cellular work.

structural support

structural support Cellulose is an example of a structural polysaccharide.

Sucrose, normal table sugar, is the most common disaccharide.

glucose

polymer ... glucose molecules ; Cellulose is a polysaccharide, constructed from many monosaccharides.

Microorganisms in their digestive tracts hydrolyze the cellulose to glucose. ; Cows have digestive chambers of microorganisms that can produce the enzymes that cows lack, in order to digest the cellulose.

starch ; Starch is the glucose-storage polymer that plants use.

starch ; Starch is a storage polysaccharide of plants.

glycogen ; Animals store a polysaccharide called glycogen.

1. cellulose (in the lettuce) ; Cellulose contains bonds that cannot be broken by human digestive enzymes.

nucleotide is to a nucleic acid. Because glucose molecules are the building blocks of starches just as nucleotides are the building blocks of nucleic acids

are not truly polymers ; Lipids are not all made of the same type of monomer. Their association as a group is related to their behavior rather than their structure.

hydrophobic ; Hydrophobic compounds are those that are insoluble in water.

Saturated triglycerides are saturated with hydrogens. Unsaturated triglycerides have double bonds in their carbon chains. Each carbon is bonded to just one hydrogen and not two.

unsaturated ; An unsaturated fatty acid has one or more double bonds.

adding hydrogens ; The phrase "hydrogenated vegetable oils" found on food labels means that unsaturated fats have been synthetically converted to saturated fats by the addition of hydrogen.

contain fewer double bonds ; Evidence suggests that a diet high in saturated fats may contribute to human cardiovascular disease.

phospholipids ; Phospholipids, by being partially water-soluble, are suitable for holding the cell membrane in place.

lipids ; Steroids, such as cholesterol, are lipids characterized by a carbon skeleton consisting of four fused rings.

Anabolic steroids can prevent bone growth.

THG was structurally manipulated.

storage ; Ovalbumin is considered to be a storage protein source for the developing embryo.

20

amino acid molecules ; Polymers of amino acids are called polypeptides. A protein consists of one or more polypeptides folded into specific conformations.

1. R-NH2

a covalent bond ; The covalent bond joining two amino acids is a peptide bond.

A polypeptide is a chain of amino acids that have been linked together by dehydration synthesis.

1. tertiary structure

It is the sequence and arrangement of the 20 amino acids that determines the shape of a protein and thereby the function. Different sequences can yield different proteins.

a dehydration reaction between the amino group of one amino acid and the carboxyl group of a second amino acid

4. changing the concentration of salt in the environment

the number and sequence of amino acids ; The primary structure of a protein is its unique sequence of amino acids.

secondary structure;. Both the alpha helix and the pleated sheet are polypeptides held in a given structure by hydrogen bonds.

tertiary structure = The tertiary structure is determined by hydrogen bonds, hydrophobic groups, and ionic bonds between R groups.

It involves two or more polypeptide chains. ; All other levels of protein structure involve only a single polypeptide chain.

quaternary structure = The quaternary structure is the combination of more than one polypeptide chain in a protein. In the case of collagen, there are three polypeptide strands twisted together.

They are large polymers. ; Both can be very long, although many small proteins are biologically active.

1. different sugars (Deoxyribose vs. Ribose) 2. different nitrogenous bases (thymine vs. uracil) 3. RNA is single stranded, DNA is double

a nitrogenous base, a phosphate group, and a sugar ; Each nucleotide consists of three parts: an organic molecule, called a nitrogenous base; a sugar; and a phosphate group.

DNA The backbone of a nucleic acid consists of alternating sugar and phosphate groups.

that was advantageous to individuals after the age of 2. Lactose tolerance became prevalent in people of Northern European descent because it offered a survival advantage. Milk became an essential food source for these individuals because the climate only offered one harvest a year and milk was available year-round.