Biology - Unit 2: Biomolecules

Anabolism

The formation of larger molecules from smaller ones, including macromolecules from monomers by condensation.

Catabolism

The breakdown of complex molecules into simpler ones by hydrolysis.

Macromolecule

A very large organic molecule composed of many smaller molecules (monomers).

Monomer

A simple compound whose molecules can join together to form polymers (macromolecules).

Hydrolysis

A chemical reaction that breaks apart a large molecule by adding a molecule of water.

Condensation

A chemical reaction in which two molecules become covalently bonded through the loss of a water molecule.

Monosaccharide

A single sugar molecule such as glucose or fructose, the simplest type of sugar.

Disaccharide

A sugar made from two monosaccharides linked together (e.g. glucose + fructose → sucrose).

R group

The variable radical of amino acids, shown as R- in diagrams.

Amino acid

Molecules that make up proteins; made of a carbon atom, carboxyl group, amine group, hydrogen, and an R-group.

Lipids

Fats made of carbon, hydrogen, and oxygen; examples include oils, waxes, phospholipids, triglycerides, and steroids; functions: energy storage, thermal insulation, hormones.

Polypeptide

A polymer (chain) of amino acids linked by peptide bonds.

Water molecule

A polar molecule made of one oxygen and two hydrogen atoms.

Polarity

Having positively and negatively charged areas due to uneven electron distribution.

Hydrogen bond

A weak bond formed between polar water molecules.

Cohesion

Hydrogen bonds make water molecules stick together strongly, causing surface tension; stronger at lower temperatures.

Carbon Dioxide

An inorganic molecule containing carbon and oxygen. Draw a diagram.

Glucose

A monosaccharide used as an energy source in plants and animals; found in human blood.

Maltose

Disaccharide between glucose and glucose.

Fructose

Monosaccharide that makes sucrose; found in fruits

Galactose

Monosaccharide that makes lactose; found in milk

Sucrose

Disaccharide between glucose and fructose. The transport sugar in plants (from leaves to roots); cane sugar.

Cellulose

A polysaccharide using beta-glucose; forms plant cell walls; can be very long.

Glycogen

A polysaccharide of glucose; energy storage in animals.

Starch (amylose)

A polysaccharide used to gain glucose for energy; found in plants.

Fatty acids

Can be saturated or unsaturated (mono or poly) based on presence or absence of double bonds between carbons.

Triglyceride

A lipid storing more energy per gram than carbohydrates (long-term energy storage).

Ribose

A sugar that forms the backbone of RNA.

Lactose

The main carbohydrate found in milk.

Amino acid

Monomer that makes up polypeptides.

Amino acid sequence

The order of amino acids in a protein, coded for in genes.

Rubisco

An enzyme important in photosynthesis; catalyzes addition of carbon dioxide in the Calvin cycle.

Insulin

A peptide hormone produced by the pancreas; allows liver and muscle cells to take glucose from the blood (lowers blood glucose).

Collagen

A strong triple-helix protein fiber found in bone, tendons, ligaments, etc.

Spider silk

Exceptionally strong, elastic, lightweight silk produced by spiders.

Immunoglobulin

Antibodies (proteins) secreted by B-cell lymphocytes.

Proteome

All proteins a cell or organism can make; each individual has a unique set.

Polypeptide

A polymer (chain) of amino acids linked by peptide bonds.

Deoxyribose Sugar

With phosphate, forms the backbone of DNA.

Phosphate group

Together with sugar, makes the backbone of DNA.

Nitrogenous Base

One of four bases; their order creates the genetic code.

Complementary pairing

A pairs with T; C pairs with G.

Hydrogen bond

The weak bond holding the two strands of DNA together.

Double helix

The twisted, double-stranded shape of DNA.

Covalent bonds

Strong bonds holding base, sugar, and phosphate together.

Polymer

Refers to DNA and RNA, both made from long chains of nucleotides.

Difference between DNA and RNA

DNA is double-stranded, RNA is single-stranded; DNA has deoxyribose, RNA has ribose; DNA uses thymine, RNA uses uracil.

Antiparallel strand

DNA strands that run alongside each other but one is upside down.

Watson and Crick

Scientists who modeled DNA structure using Franklin’s data.

Enzymes

Proteins that act as biological catalysts to speed reactions.

Peptide bond

The covalent bond between amino acids, formed between amine and carboxyl groups.

Primary structure

The polypeptide chain and amino acid sequence; determines all other levels of structure.

Secondary structure

Folding of amino acids into alpha helices or beta-pleated sheets.

Tertiary structure

Complex 3D folding caused by interactions between R-groups; includes fibrous and globular proteins.

Quaternary structure

Interaction between multiple polypeptides or prosthetic groups; not all proteins have this level.

Denaturation

Structural change in a protein causing loss of biological function; usually caused by temperature or pH.

Fibrous protein

Structural role; exposed hydrophobic R groups; insoluble; long and narrow; less sensitive to heat

Globular protein

Functional role; hydrophobic R groups folded inward; soluble; spherical; sensitive to heat

Codon

Triple DNA bases that code for specific amino acids; multiple codons form a polypeptide chain