ap bio study macromolecules

Organic Molecule

A molecule that contains carbon atoms bonded to other carbon atoms.

Carbohydrates

One of the four types of organic compounds.

Proteins

One of the four types of organic compounds.

Lipids

One of the four types of organic compounds.

Nucleic Acids

One of the four types of organic compounds. NA

Carbohydrates - C, H, O

The elements that compose carbohydrates.

Proteins - C, H, O, N, sometimes S

The elements that compose proteins.

Lipids - C, H, O

The elements that compose lipids.

Nucleic Acids - C, H, O, N, P

The elements that compose nucleic acids.

Carbon's characteristics

Carbon has four valence electrons, can form four different bonds, can form chains, branches, rings, unique 3-D shapes, strong and stable bonds, single, double or triple bonds, does not readily dissociate in water, has no limit to molecule size, and can bond with a wide variety of other elements and functional groups.

Hydrocarbon

An organic molecule consisting only of carbon and hydrogen.

Functional Group

A small, specific group of atoms that can be attached to a carbon skeleton.

Functions of Functional Groups

They give the molecule its unique shape and behave a certain way in chemical reactions.

Hydroxyl

A functional group (-OH) found in sugar molecules that makes molecules very polar.

Carbonyl

A functional group (-C=O) found in sugar molecules that makes molecules very polar.

Carboxyl

A functional group (-COOH) found in proteins and lipids that makes molecules very polar and has acidic properties.

Amino

A functional group (-NH2 or -NH3+) found in all amino acids.

Sulfhydryl

A functional group (-SH) found in the amino acid cysteine that forms disulfide bridges in the tertiary structure of a protein.

Phosphate

A functional group (-PO4) found in phospholipids, DNA, RNA, and ATP.

Building blocks of carbohydrates

The simple sugars such as glucose.

Recognition of simple sugars

They consist of C, H, and O in a 1:2:1 ratio and have both hydroxyl groups and carbonyl groups.

Building blocks of lipids

Fatty acids and glycerol.

Recognition of glycerol

It is a 3-carbon compound with hydroxyl on each carbon.

Recognition of fatty acid

It has a very long carbon skeleton with a carboxyl group at one end.

Building blocks of proteins

Amino acids.

Recognition of an amino acid

It consists of a carbon atom bonded to a carboxyl group, an amino group, one single hydrogen, and an 'R' group which varies in each amino acid.

Number of amino acids

20

Nitrogenous base

It is a ringed structure with carbon and nitrogen alternating in the ring, which may have a single ring or a double ring.

Nitrogen bases

Adenine, Thymine, Cytosine, Guanine.

Purines and pyrimidines

purine a nitrogen base with 2 rings - adenine and guanine.

Adenine

Thymine

Cytosine

Guanine

Purine

A nitrogen base with 2 rings - adenine and guanine.

Pyrimidine

A nitrogen base with 1 ring - cytosine and thymine.

Macromolecules

"Giant" molecules that are formed by the joining of many smaller molecules.

Polymer

A long molecule consisting of many similar or identical building blocks linked together by covalent bonds.

Monomers

Smaller molecules that are the repeating subunits that are joined together to make polymers.

Monomers of carbohydrates

Molecules of simple sugars such as glucose.

Monomers of proteins

Amino Acids

Dehydration reaction

The reaction that joins two monomers together by removing a water molecule.

Hydrolysis reaction

Polymers are disassembled to monomers by hydrolysis, breaking bonds by the addition of a water molecule.

Examples of carbohydrates

Sugars, starches, and celluloses.

Classification of carbohydrates

By the number of sugar monomers composing them.

Levels of sugar composition

Monosaccharides - One molecule of sugar; Disaccharides - Two molecules of sugar bonded together; Polysaccharides - Many molecules of sugar bonded together.

Purpose of simple sugars

Glucose is the principal energy source of all living organisms and can serve as raw materials for the synthesis of other biological molecules.

Glycosidic linkage

A covalent bond formed between 2 monosaccharides by a dehydration reaction.

Purpose of disaccharides

Sugars are transported throughout a plant in the form of disaccharides.

Types of polysaccharides

Structural Polysaccharides and Storage Polysaccharides.

Storage polysaccharide

Starch - How plants store excess glucose; Glycogen - How animals store excess glucose.

Structural polysaccharide

Cellulose - Forms the tough, fibrous material in plant cell walls; Chitin - Used by arthropods for exoskeletons and by fungi in cell walls.

Types of lipids

Fat, Oil, Wax, Phospholipids, Cholesterol.

Distinguishing characteristic of lipids

They are nonpolar and not soluble in polar solvents such as water.

Simple sugar

A molecule with only C, H, and O in a 1:2:1 ratio.

Amino acid

A molecule with a central carbon atom bonded to a carboxyl group, an amino group, a single hydrogen, and an 'R' group.

Lipid

A molecule with one glycerol and three fatty acid tails.

Glycerol

The portion of the molecule shown in gray.

Fatty Acid

The portion of the molecule shown in orange.

Saturated fatty acid

They contain NO carbon-to-carbon double bonds. As many hydrogen atoms as possible are bonded to the carbon atoms. no s

Unsaturated fatty acid

They DO contain carbon to carbon double bonds. There will be a "kink" in the tail wherever a double formed is found.

Healthier unsaturated fatty acids

The "kinky tails" of the unsaturated fats prevent them from packing too close together. They form liquids at room temperature.

Saturated fatty acids

They have no kinks and will pack very closely together, forming solids. These may lead to cardiovascular diseases.

Uses of Lipids

Good source of energy. They are used to insulate the body. They cushion the internal organs. Phospholipids are a structural component of membranes.

Phospholipids

They are composed of glycerol, but only have 2 fatty acid tails instead of three. One tail is saturated, the other is unsaturated.

Arrangement of lipids in a membrane

There is a double layer (bilayer) of lipids in the membrane. The hydrophilic glycerol head is found on the outer edge and the inner edge of the membrane. The hydrophobic fatty acid tails point to each other across the middle of the membrane.

Importance of lipid arrangement

The glycerol molecules draw water to the membrane, but the hydrophobic fatty acid tails make the membrane insoluble in water.

Purpose of wax in biological systems

Wax is generally used as a water proofing material on leaves, fruits, feathers, fur.

Purposes of proteins

Enzymes, Hormones, Transport (hemoglobin), Contractile (muscle tissue), Antibodies, Membrane structure, Structural proteins.

Peptide bond

A covalent bond formed by a dehydration reaction that links the carboxyl group of one amino acid to the amino group of another amino acid.

Polypeptide

A chain of amino acids held together by peptide bonds. It is not yet a fully functioning protein.

Protein shape and function

Shape determines function!

Four levels of protein organization

Primary, Secondary, Tertiary, Quaternary.

Primary structure of a protein

The unique sequence of amino acids that are put together by the ribosomes of the cell.

Secondary structure of a protein

The initial folding and shaping of the polypeptide. It is the repetitive folding due to the formation of hydrogen bonds at regular intervals.

Tertiary structure of a protein

Irregular contortions of a protein due to bonding between side chains. Tertiary structure gives the protein its shape. It is due to hydrophobic interactions and disulfide bridges.

Hydrophobic interactions

The clustering of hydrophobic side chains at the center of the protein.

Disulfide bridges

Covalent bonds between the side chains of two cysteine amino acids. The sulfur of one cysteine bonds to the sulfur of the second.

Quaternary structure of a protein

Two or more polypeptide subunits combine to form a functional protein.

Denatured protein

A denatured protein has lost its unique, 3-D shape. It is inactive and can no longer carry out its function.

Types of nucleic acids

DNA and RNA.

Components of nucleic acids

Nucleotides.

Components of a nucleotide

Sugar, phosphate, nitrogen base.