Biochemistry

what are atoms?

single unit made of neutrons, protons, and electrons

what are molecules?

groups of 2 or more atoms held together by chemical bonds due to electron interactions

what are macromolecules?

large molecules (polymers) formed from the bonding of smaller molecules (monomers)

what are ionic bonds?

transfer of electron from one atom to another atom of very differing electronegativity (typically done to help fill valence shells)

what are covalent bonds?

sharing of electrons between atoms of similar electronegativities

what are the two types of covalent bonds? how are they different?

nonpolar and polar

nonpolar: equal electron sharing

polar: unequal electron sharing that results in the formation of a dipole

what are hydrogen bonds?

hydrogen bonds are weak bonds between a hydrogen atom and an electronegative atom (N,O,F)

how are macromolecules formed?

dehydration reaction: links monomers to form polymers, and forms water in the process

how are macromolecules broken down?

hydrolysis: water is used as an input to break polymers into monomers

what are the monomers of proteins?

amino acids

what is the polymer of a protein called?

peptide chain

what type of bond links proteins?

peptide bonds

what is the function of proteins?

structural help, transportation, defense, storage, enzymes

what are the 4 structures of proteins?

primary, secondary, tertiary, quarternary

what is a primary protein?

linear chain sequence of amino acids

what is a secondary protein?

local folding of amino acid chain into alpha helices and beta sheets via hydrogen bonding between amino and coarboxyl groups of the adjacent amino acids

what is a tertiary protein?

3D shapes of proteins formed due to noncovalent interactions between the R groups of proteins

which covalent bond is the exception in tertiary protein formation?

disulfide bonds

what is a quaternary protein?

3D protein shape consisting of 2+ separate peptide chains

how many polypeptide chains are in a teritary protein?

1

what is the structure of an amino acid?

4 components attached to a central carbon:

1. amino (NH₂) group

2. carboxyl (COOH) group

3. R group

4. Hydrogen

what is the polarity and water affinity of lipid molecules?

nonpolar and hydrophobic molecules

what is a monomer of lipids?

hydrocarbon

what is a polymer of lipids?

hydrocarbon chain

what are triglycerides?

glycerol + 3 fatty acids

• saturated (single bonds, straight chain)

• unsaturated (double bonds, branched chain)

what are phospholipids?

2 fatty acids + phosphate group atatched to a glycerol backbone

• amphipathic with a polar head and nonpolar tail

• form phospholipid membrane bilayer

what are steroids?

3 6-membered rings + 1 5-membered ring

• Examples include hormones and cholesterol

what are the 3 types of lipids?

triglycerides, phospholipids, steroids

what are porphyrins?

4 joined pyrrole rings with a metal center atom

• examples include chorphyll and hemoglobin

• non-lipids but are commonly asscoiated with the lipid membrane

what are the monomers of nucleic acids?

nucelotides

what are the polymers of nucleic acids?

nucleic acids themselves!

ex: DNA or RNA

what is the bond linkage between nucleotides?

phosphodiester bonds

what is the function of nucleic acids?

encode, express, and store genetic information

what is the function of carbohydrates?

to store energy

what is the function of lipids?

insulation, energy storage, endocrine signaling, cell structure

what is the linkage type between lipids?

covalent carbon-carbon bonds

what is the structure of a nucleotide?

1. nitrogenous base

2. phosphate group

3. sugar

what sugar does DNA contain and what is attached to that sugar?

deoxyribose and is has an H attached to the 2’ carbon of the sugar

what sugar does RNA contain and what is attached to that sugar?

ribose and is has an OH attached to the 2’ carbon of the sugar

what are two important factors of DNA?

DNA strands run antiparallel and they are complimentary to one another

what kind of nitrogenous bases are A and G? how many rings do they have?

purines; 2 rings

what kind of nitrogenous bases are T and C? how many rings do they have?

pyrimidines; 1 ring

how many hydrogen bonds form between A and T?

2

how many hydrogen bonds form between C and G?

3

what does C and G having more H bonds than A and T indicate for the strand?

DNA strand will require a higher temperture to dentaure the C and G bonds versus the A and T bonds

is RNA single or double stranded?

RNA is single stranded

what is chargaff’s rule?

A & T are always present in equal amounts and G & C are always present in equal amounts

what are the monomers of carbohydrates?

monosaccharides (single sugar molecule)

• ex: glucose

what are the polymers of carbohydrates?

polysaccharides (polymer of sugar molecules)

• ex: glycogen, cellulose, chitin

what is the linkage type between carbohydrates?

glycosidic bonds

what are 2 joined sugar molecules called?

disaccharides

• ex: sucrose = glucose + fructose