BISC220 Lecture 1 & 2

where do you find protons?

clustered in nucleus

what’s the charge of a proton?

positive charge

where do you find neutrons?

clustered in nucleus

what’s the charge of a neutron?

neutral charge

where do you find electrons?

scattered around nucleus in valence shells

what’s the charge of an electron?

negative charge

what’s a valence shell?

outermost regions of an atom where electrons can exist

how many electrons needed to fill innermost valence shell?

2

how many electrons needed to fill all valence shells after the innermost shell?

8

when is an atom considered unstable?

when valence shells are incomplete

what are ions?

atoms with an electrical charge

what do ions do?

signal and maintain balance of bodily fluids in biology

what are isotopes?

atoms that have an uneven number of neutrons relative to the number of protons

what happens to isotopes overtime?

they’re radioactive, so they decay overtime and emit energy

what’s an isomer?

compounds that share the same chemical formula, but may vary in structural arrangement

what are the different types of isomers?

structural, geometric, enantiomers

what’s a structural isomer?

they exhibit different arrangements of the atoms that make up the compound

what’s a geometric isomer?

they exhibit different angle/orientation based on the presence of single or double covalent bonds

what’s an enantiomer?

“mirror images” of one another. particularly useful in pharmacology

elements most important to biology

CHONPS: carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur

what’s an ionic bond?

metal (usually a cation) and nonmetal (usually an anion) elements form a bond. metal donates an electron to the nonmental, relationship typically uneven.

what are common examples of ionic bonds?

sodium chloride (NaCl, table salt), sodium hydroxide (NaOH, bleach)

what’s a covalent bond?

two nonmetals bond. sharing of electrons, relationship somewhat equal

what are common examples of covalent bonds?

Dihydrogen oxide (H2O, water), methane (CH4)

why can hydrogen form hydrogen bonds?

hydrogen is the smallest element on Earth, so it can form special transient bonds

what are the properties of water?

1. water is polar
2. universal solvent
3. high heat capacity
4. high heat of vaporization
5. high cohesion + adhesion
6. less dense as a solid than as a liquid

how does hydrogen affect pH?

more hydrogen ions (H+)- more acidic (pH

what’s a monomer?

a single chemical unit, or a building block for a larger molecule

what’s a polymer?

a molecule that consists of several monomers bound together

what are carbohydrates?

a class of macromolecules that are commonly known as sugars. Composed of CHO. Some carbohydrates are known as saccharides.

MIGHT NEED TO KNOW?

TYPES OF POLYSACCHARIDES

MIGHT NEED TO KNOW?

PROTEIN STRUCTURE OF AMINO ACIDS (TABLE IN SLIDES)

what are lipids?

class of macromolecule that are commonly known as fats. composed exclusively of CH. not water soluble because their chemical structure makes them a nonpolar covalent molecule.

can nonpolar molecules dissolve in polar molecules?

no. e.g nonpolar molecules can’t dissolve in water, a polar molecule. “like dissolves like”.

what are 3 common lipids?

triglyceride, phospholipid, steroid

what is the structure of a saturated fatty acid?

CHO, no double bonds

what is the structure of an unsaturated trans fatty acid?

CHO, double bond, H atoms opposite

what is the structure of an unsaturated cis fatty acid?

CHO, double bond, H atoms same side, bent configuration

what are proteins (peptides)?

largest and most important class of macromolecules. CHON minimum elements required, sometimes contains S

what’s the monomer for proteins?

amino acids. can bind together to form polymer (polypeptide)

how many naturally occurring amino acids important for life on Earth are there?

20

what are the different types of protein structure?

primary, secondary, tertiary, quaternary

what is primary protein structure?

polypeptide chain

what is secondary protein structure?

alpha helix + beta sheets produced by hydrogen bonds forming within the polypeptide

what is tertiary protein structure?

3D overall fold of the protein containing secondary structures

what is quaternary protein structure?

multi-subunit complex where each unit is a distinct polypeptide chain

what’s an enzyme?

a special type of protein that performs a catalytic function- reduces the energy threshold required for a specific reaction to occur, allowing the reaction to proceed at a faster rate. can be anabolic or catabolic.

what are nucleic acids?

a group of macromolecules that include several important, high-energy compounds for cells, including Adenosine Triphosphate (ATP). CHONP.

what is a nucleotide?

a common monomer for nucleic acids consisting of a nitrogenous base, a phosphate group (PO4-), and a sugar (typically ribose)

Compare DNA & RNA

DNA: double stranded, Thymine, No oxygen on sugar

RNA: single stranded, Uracil, Oxygen on sugar

what is the central dogma of biology?

Genetic information flows from DNA to RNA to Polypeptide through transcription and translation