intro to biology & chemistry for vet techs

systems biology

study of organisms and how they interact with their environment/other organisms

homeostasis

the stability of internal conditions

null hypothesis

initial hypothesis

element

a specific substance that cannot be broken down into simpler substances by chemical reactions

how many total elements are there?

118

how many elements are naturally occurring?

94

nucleus

central region of an atom

neutron

no charge particles within nucleus

proton

positively charged particles within nucleus

electrons

negatively charged particles scattered/orbiting around/outside the nucleus

atom

the smallest component of an element that retains all chemical properties of that element

the number of electrons is ____ to the number of protons

equal to

valence electrons

exist in the outer shell, important for chemical reactions

the number of protons is ____ to the atomic number

equal to

atomic mass

(number of protons) + (average number of neutrons)

isotopes

when atoms of the same element have the same number of protons but different numbers of neutrons

ionic bonds

involve 1 atom losing 1 or more electrons and another atom gaining the electrons that were lost by the first atom

ion

atom with a charge

anion

ion w/ negative charge

cation

ion w/ positive charge

covalent bond

when electrons are shared to achieve a full outer shell

molecules

the result of atoms being joined by covalent bonds (smallest unit of a compound)

compound

contain @ least two differeent elements

nonpolar covalent bonds

when two covalently bonded atoms share electrons nearly equally (ex: oxygen molecule O2)

polar covalent bonds

when electrons are shared unequally due to a difference in charge between the atoms, developing a slightly positive/negative charge at each pole of the bond (ex: water molecule H2O)

cohesion

water attracted to itself (ex: surface tension)

adhesion

water attracted to other substances (ex: towel soaking up water)

acid

substance that increases the concentration of hydrogen ions in a solution

base

provides hydroxide ions (or other negatively charged ions) that combine with hydrogen ions, therefore decreasing their concentration in a solution

pH

indicates acidity or alkalinity of a solution

weak bases or acids will only

partially dissociate

pH ranges from

0 to 14

on the pH scale of 0 to 14, 0 is ___ and 14 is ___

acidic, basic

7 on the pH scale is?

neutral

a pH change of one unit indicates a change of how much in hydrogen ion concentration?

tenfold

equation to solve for hydrogen ion concentration

[H+] = 10^-pH

the 4 types of macromolecules

proteins, carbohydrates, lipids, nucleic acids

what atom forms the basis of life and is central to compounds and molecules that impact biological functions?

carbon

made of amino acids, these control the structure and function of cells

proteins

amino acids

molecules with a central carbon that binds to a hydrogen atom, two functional groups, and a variable side group (R group)

R group

unique chemicla properties that makes each amino acid its own

chains of many amino acids connected by peptide bonds becomes this:

a polypeptide chain

amino acids that can’t be synthesized by the body (and need to be obtained via diet) are considered

essential amino acids

peptides are made from

two or more amino acids

how are peptide bonds formed?

via a dehydration reaction, involving the loss of a water molecule

how are amino acids polymerized into peptides and proteins?

through the formation of a peptide bond

nonessential amino acids

made by the body

this class of proteins catalyzes reactions

enzymes

these proteins are essential for the immune system

antibodies

these proteins make up cells (ex: keratin forming hair and nails)

structural proteins

what does this image depict?

the basic breakdown of an amino acid

what is the #1 in this image?

amino group

what is the #2 in this group?

carboxyl group

what is the #3 in this group?

the variable side group or R group

this image depicts what?

alpha-helix

alpha-helices occur when?

when hydrogen bonds between an amino hydrogen and a carbonyl oxygen causes the peptide to form a spiral or helical structure

this image depicts what?

beta-pleated sheet

beta-pleated sheets occur when?

there is hydrogen bonding between amino acids and carbonyl oxygens, causing portions of the polypeptide chain to turn back on itself like an accordion

what determines the function of a protein?

its tertiary structure

the three-dimensional shape (or tertiary structure) of a protein is largely driven by what?

the hydrophobic areas of the protein that prefer to be buried inside of a cell structure, or due to interactions between different R groups associated with the amino acids

some proteins also have a quaternary structure which is?

the arrangement of multiple polypeptide chains to form a larger protein

true or false: quaternary structures can also affect function (ex: hemoglobin, insulin, etc.)

true

protein structures are sensitive to changes in pH, temperature, and salt concentration. changes in these can cause what?

protein denaturation

protein denaturation

the process of a protein unfolding from its natural structure

what is the primary energy source for plants and animals?

carbohydrates

monosaccharides, disaccharides, and polysaccharides are all examples of what?

carbohydrates

monosaccharides

single sugars, the simples form of carbohydrate that cannot be broken down

monosaccharides have _____ on their carbons, allowing them to form hydrogen bonds with water, making them _____

alcohol groups, water-soluble

biopolymers

polymers of biological molecules

polysaccharides are a type of what?

biopolymer

glycogen

stores energy in the muscles and livers of humans/animals

starches

water-soluble, helical structures with alcohol groups readily available for hydrogen bonding. used to store energy in plants

cellulose

forms hydrogen bonds between its strands to form sheets, making it insoluble and more rigid

cellulose is the technical term for what?

dietary fiber

nonpolar, water insoluble molecules found in cells/tissues of living organisms are known as?

lipids

simple lipids contain only:

carbon, hydrogen, and oxygen

fatty acids

simple lipids that have long chains of carbon atoms bonded only to hydrogen, with a carboxyl group (-COOH) at the end

four major groups of lipids

fatty acids, phospholipids, steroids, waxes

waxes

fatty acids with long chain alcohols, often coating leaves of plants or functioning as a water repellent

triglycerides

fatty acids with glycerol

triglycerides are considered ___ if they’re solid at room temperature, and ___ if they’re liquid at room temperature

fats, oils

unsaturated fats

contain at least one double bond, obtained from foods such as fish/avocados/tree nuts

saturated fats

fats without any carbon double chain bonds, therefore “saturated with” hydrogen atoms

phospholipids

important building blocks of the cell membrane. similar to fatty acids but have a phosphate group at the end

steroids

simple lipids that serve as important components of cell membranes for membrane fluidity and as signaling molecules. characterized by a base structure of four connected hydrocarbon rings

four important steroids

testosterone, estrogen, cholesterol, prednisone