Molecules of Life

These flashcards summarize the key vocabulary and concepts from the Molecules of Life module.

Atom

The basic unit of matter, containing protons, neutrons, and electrons.

Covalent Bond

A strong bond formed when two atoms share electrons.

Ionic Bond

A bond formed when one atom steals an electron from another, resulting in charged ions.

Hydrogen Bond

A weak bond that forms between a hydrogen atom and an electronegative atom, such as oxygen.

Organic Molecule

A molecule that contains carbon and is found in living organisms.

Monomer

A small building block that links together to form polymers.

Polymer

A large molecule made up of repeating monomer units.

Condensation Reaction

A reaction that combines monomers and releases water as a byproduct (requires energy)

Hydrolysis Reaction

A reaction that breaks down polymers into monomers by adding water (releases energy)

Hydrophilic

Molecules that are attracted to water and can dissolve in it.

Hydrophobic

Molecules that repel water and do not dissolve in it.

pH

A measure of the concentration of hydrogen ions in a solution.

Proteins

Macromolecules that provide structural support, act as enzymes, cell signalling/regulation, movement, support, defence (perform various functions in cells)

Carbohydrates

Biological molecules made of carbon, hydrogen, and oxygen with 1:2:1 ratio (any can be), serving as energy sources (and structural support)

Lipids

Hydrophobic, chemically diverse group of molecules that include triglycerides, steroids, and phospholipids, important for membrane structure, storing energy, and cell communication.

Nucleic Acids

information molecules that store and transmit genetic information in the series of nucleotides; includes DNA and RNA.

Functional Group

A specific group of atoms that imparts characteristic properties to a molecule.

Valence Electrons

Electrons in the outermost shell of an atom that participate in chemical bonding.

Saturated Fatty Acid

A fatty acid with no double bonds between carbon atoms, solid at room temperature.

Unsaturated Fatty Acid

A fatty acid with one or more double bonds, liquid at room temperature.

Polysaccharide

A carbohydrate made up of many monosaccharides linked together.

Peptide Bond

The covalent bond formed between two amino acids during protein synthesis.

Phospholipid

A type of lipid that forms the bilayer of cell membranes, consisting of a hydrophilic head and two hydrophobic tails.

molecules

more than one atom

polar covalent bond

unequal sharing of electrons

nonpolar covalent bond

equal sharing of electrons

water

medium of life and most abundant molecule in biological organisms - universal solvent

H atoms

they form H-bonds with highly electronegative atoms (NOF)

importance of pH

for cellular function

removal of water in human cells

dry mass consists of mostly C, H, O, and N

polar functional group

N, O, P, S in functional group (more electronegative)

nonpolar functional group

contrasted with a methyl group (CH3)

enzymes

catalysts that accelerate rate of chemical reactions

common functional groups in biological molecules

amino (NH), amide (C(=O)NH), carboxyl (COOH), carbonyl (C=O), hydroxyl (OH), sulfhydryl, (SH) methyl (CH3), phosphate (OPO3H2)

polypeptide

polymer of proteins

amino acids

monomer of protein

general structure of amino acid

carboxyl, amino, hydrogen, and R group

pH 7.4 for amino acids

carboxyl and amino group ionized and amino acid has postive and negative charge (a zwitterion) - covalent bond

zwitteron

molecule that has postive and negative charge (results in neutral)

deoxyribonucleic acid

the genetic material in all celuular organisms with information used to direct protein synthesis

ribonucleic acid

has multiple functions - is the key-player in protein synthesis and regulation of gene expression

pyrimidine base

part of nucleotide - nitrogenous base that has single ring (C and T)

purine base

part of nucleotide - nitrogenous base that has double ring (A and G)

5-carbon sugar

part of nucleotide (in DNA or RNA)

one or more phosphate groups

part of nucleotide

nucleoside

has 2 parts - base and sugar

nucleotide

the monomer of nucleic acids; has 3 parts - base, sugar, at least one phosphate

connecting nucleotides

chain is always built 5’-3’by adding nucleotides at the 3' end.

covalent linkage in nucleotides

linkage between the phosphate group of one nucleotide to the sugar unit 3’-OH on another (phosphodiester)

phosphodiester bond

the bond for nucleic acids

anti-parallel arrangement

sugar-phosphate backbone wraps around the outside

benefit of hydrogen bonds between nucleotide bases

allows DNA to unzip down the middle

3H-bonds

c-g

2 H-bonds

A-t

6-carbon sugars

C6H12O6

monosaccarides

simple sugars, virtually in cyclic forms

aldehyde group

a functional group (carbonyl) with one hydrogen atom attached and a carbon based group on carbonyl carbon

ketone group

a functional group (carbonyl) with two carbon-based groups attached to the carbonyl carbon.

glycosidic bond 

linkage found in carbohydrates

disaccharide

monomer of carbohydrates (linking two monosaccharides)

oligosaccharides

FEW monosaccharides joining

polysaccharides

more than two monosaccharide monomers link (poly=MANY)

starch

branch of glucose molecules (polysaccharide) used for energy storage in plants.

glycogen

large branched chain of glucose molecules (polysaccharide) used for energy storage in animals (+fungi and bacteria).

triacylglycerol

major component of animal fat and vegetable oil with THREE fatty acids and glycerol

fatty acid

long chain of carbons attached to a carboxyl group at one end

saturated fatty acid

a type of fatty acid with no double bonds between carbon atoms, resulting in a straight structure.

unsaturated fatty acid

a type of fatty acid that contains one or more double bonds between carbon atoms, resulting in a kinked structure.

glycerol

a 3-carbon molecule with hydroxyl group attachedto each carbon

steroids

many carbon atoms bonded to characteristic four fused rings

cholesterol

steroid found in animal cells. Steroids are derived from cholesterol

phospholipids

a major component of cell membranes made up of glycerol backbone attached to a polar phosphate group (hydrophillic head) and two fatty acid tails (nonpolar, hydrophobic tail)

amphipathic

molecules with both hydrophillic and hydrophobic regions