Cell Physiology Tutoring

matter

Anything that has mass and takes up space

mass

the amount of matter in an object

weight

A measure of the force of gravity on an object

volume

The amount of space an object takes up

with a chemical change there (is/is not) a change in the molecular structure

There is a change

with a physical change there (is/is not) a change in the atomic structure

there IS NOT a change

how many elements are used in the makeup of the human body

40

period

a row from left to right on the periodic table

within a period, all elements have the same number of what?

atomic orbitals

group

a vertical column on the periodic table

within a group, all elements have the same number of what?

valence electrons

valence electrons

the elements in the outermost shell or energy level

valence electrons determine?

reactivity of an element

What is the maximum number of valence electrons in the outer shell?

8

octet rule

the tendency of atoms to have 8 valence electrons in its outermost shell

if an atom has a full octet in their outermost shell, will it react?

NO

ions

atoms that have a net charge due to loss or gain of electrons

if an ion has a positive charge (Na+) it has...

lost electrons

if an ion has a negative charge (Cl-) it has...

gained electrons

Cation

A positively charged ion

anion

A negatively charged ion

ionic bonds

attraction between oppositely charged ions

ionic combination that will form an ionic bond?

cation + anion

Electronegativity

an atoms electron attracting capability

a _______ electronegativity means an atom has a ________ electron-attracting capability

high, high

a ______ electronegativity means an atom has a _______ electron-attracting capability

low, low

covalent bond

formed by equal sharing of electrons between atoms

a covalent bond is formed between...

nonmetals and nonmetals

Two bond types of covalent bonds

sigma and pi bond patterns

nonpolar covalent bond

two electrically neutral atoms are sharing electrons

polar covalent bond

one atom has a higher electronegativity, so it pulls more of the electron density toward itself

hydrogen bonds

a hydrogen atom, already covalently linked to another electronegative atom (O, N, F) is attracted to a lone pair of electrons on another O, N, F

hydrogen bonding is common among...

water molecules

hydrogen bonds between water molecules allow water to display a tendency known as

surface tension

when you boil water, the heat breaks bonds, which bond will the head break first?

hydrogen bonds

Hydrophilic

Attracted to water, these are substances such as ionic compounds that have charges and polar molecules

hydrophobic

water hating, these are substances such as non-charged molecules such as fats and nonpolar molecules

van der waals

weak, attractive forces between molecules that arise from temporary fluctuations in electron density

intermolecular forces

attractive forces between molecules (ex: hydrophobic/hydrophilic)

intramolecular forces

hold atoms together within a molecule (ex: covalent bonds)

four main macromolecules

carbohydrates, lipids, proteins, nucleic acids

amino acid

basic functional unit of a protein

peptide bond

the bond type that links amino acids together

basic structure of an amino acid

a single covalently bonded hydrogen, amino group, carboxyl group, R-group

examples of non-polar amino acids

proline and glycine

examples of polar amino acids

tyrosine

Positively charged amino acids

arginine

negatively charged amino acids

aspartic acid, glutamic acid

hydrophobic amino acids

poorly water-soluble and side chains are nonpolar

hydrophilic amino acids

water soluble and side chains are polar

non-essential amino acids

CAN be made by the human body, and non-essential to our diet (alanine)

conditionally essential amino acids

synthesis can be limited during pathophysiological conditions (glutamine)

essential amino acids

CANNOT be made by the human body, therefore essential to our diet (phenylalanine)

Certain amino acids can form specific bonds

Cysteine contains a sulfhydryl group that can form a disulfide bond

nucleotide

basic functional unit of a nucleic acid

phosphodiester bond

bond type that links nucleotides together

basic structure of a nucleotide

sugar base(RNA/DNA), phosphate group, nitrogenous base

DNA contains...

adenine, guanine, cytosine, thymine

RNA contains....

adenine, guanine, cytosine, uracil

Monosaccharides

basic functional unit of a carbohydrate

glycosidic bond

bond type that links carbohydrates together

basic structure of a monosaccharide

hydroxyl groups, and either a aldehyde or ketone group

fatty acid

basic functional unit of a lipid

saturated fatty acid

no double bonds=no kinks

unsaturated fatty acids

double bonds=kinks (trans fatty acids, cis fatty acids)

trans fatty acids

cause the cell membrane to become rigid (bad)

cis fatty acids

cause the cell membrane to be unable to crowd adding to membrane fluidity

primary structure of proteins

sequence of a chain of amino acids,

linked by covalent bonds

peptide

20-30 amino acids in length

polypeptide

30 or more amino acids in length

secondary structure of proteins

hydrogen bonding of the peptide backbone causing folding into repeating patterns,

linked by hydrogen bonds

secondary structure of proteins characterized as

alpha helices and beta pleated sheets

this level of structure must be present in order for a functional protein to exist

secondary structure

tertiary structure of a protein

3D folding pattern of a protein due to side chain interactions, the most stable connection is a disulfide bone

this level of structure must be present in order for complex globular proteins to exist

tertiary structure

Quanternary structure of protein

a protein consisting of more than one amino acid chain

tertiary and quaternary characteristics

BOTH form disulfide bonds, and BOTH use covalent, ionic and hydrogen bonds

kinetic energy

energy in action

potential energy

stored energy

chemical energy

Energy stored in chemical bonds

exergonic reactions

release energy and spontaneous (heat released)

reactants > products

endergonic reactions

requires energy to be added (requires external source)

reactants > products

gibbs free energy

used to determine whether a reaction is exergonic or endergonic

free energy change

delta G

negative delta G

spontaneous, energy released=exergonic reaction

positive delta G

non-spontaneous, requires energy=endergonic

zero delta G

the forward and reverse reactions occur at equal rates

Delta G equation

G= H-TS

G=gibbs free energy, H=bond strength, T=Temp, S=entropy

enzymes

protein catalysts that speed up reactions

substrates (ligand)

bind to enzymes at the active site

Things enzymes do: (enzymes are catalysts)

1. remain unchanged by the reaction

2. lower the activation energy

3. help bind reactants in the proper orientation

4. reduce random morion of reactants

5. exclude other reactants

6.expose functional groups

prokaryotic cells

These cells have one outer membrane (bacteria & archaea)

eukaryotic cells

these cells have one outer membrane, but many inner membranes (humans)

compartmentalization

this is where different cellular processes occur within distinct, membrane-bound structures called organelles

how does the cell solves some of its problems with concentration?

compartmentalization

the problem of concentration

there is a limited flow of material across the cell membrane that cannot keep up with the supply and demand of the cell

phospholipid

an amphipathic molecule with a polar phosphate head and two non-polar fatty acid tails

the phospholipid head...

is polar and hydrophilic

the phospholipid tail...

are nonpolar and hydrophobic

the tails serve as the _________ to outside molecules?

true barrier