BIOL 105 - Chapter 2: The Chemistry of Life

Everything that takes up space and has mass is called

matter

What are the elements that make up 90% of all living things?

O (oxygen), C (carbon), H (hydrogen), N (nitrogen)

What element is essential for cellular respiration and in water?

oxygen

What element is the backbone of compounds that make up life (proteins, carbohydrates, nucleic acids, and lipids)

carbon

What element is essential for bonding between water molecules and in water?

hydrogen

What element is made up on nucleic acids and proteins?

nitrogen

what is the smallest unit of an element

atom

What is in the atomic nucleus?

protons and neutrons

What is in the electron cloud?

electrons

what subatomic particle is positively charged

proton

what subatomic particle is electrically neutral

neutron

what subatomic particle is negatively charged

electrons

what is the number of protons in an atom of an element

atomic number

the number of protons and neutrons in the nucleus of an atom

mass number

what is called when the elements have the same number of protons but different numbers of neutrons

an isotope

12C (6 neutrons), 13C (7 neutrons), and 14C (8 neutrons) are all what

isotopes of carbon

what is 14C

a radioisotope

an unstable isotope used in medicine for both diagnosis and treatments

radioisotope

fundamentally depend on an atoms electron configuration, especially its valence electrons

chemical bonds

what is the outermost shell electrons

valence elctrons

energy levels

electron shell

how many electrons does the first shell of the electro shell hold

up to 2

how many electrons does the second and third shell hold in the electron shell

up to 8 each

what word is used to describe something that is not chemical active

inert

what has a filled outer electron shell so they do not need ot share, donate, or accept electrons from other atoms

inert gases

what are the examples of inert gases which are chemically unreactive?

Ne, He, Ar (most other atoms are inherently unstable)

what binds atoms together to form molecules and compounds

chemical bonds

a strong chemical attraction between oppositely charged ions (cations and anions) that form when one atom completely transfers one or more valence electrons to another

ionic bonds

positively charged ions; atoms that have lost electrons

cations

negatively charged ions; atoms that have gained electrons

anions

a bond formed when 2 atoms share one or more pairs of valence electrons (to achieve a stable electronic configuration)

covalent bond

a weak attractive force between slightly positive hydrogen atom of one molecule and slightly negative atom in another or the same molecule

- many hydrogen bonds together are relatively strongwh

hydrogen bonds

water is...

- polar

- universal solvent

- cohesive and adhesive

- high heat of evaporation and high heat capacity

- frozen less dense than liquid temperature

what does every living thing need to survive, making it the most critical natural resource

water

molecules dissociate in water, releasing hydrogen ions

acid

molecules that take up hydrogen ions or release hydroxide ions

bases

what does the pH scale indicate

acidity and basicity (alkalinity) of a solution

substance with more H and less OH - pH less than 7

acid

substance that has more OH and less H - pH greater than 7

base

substance has equal H and OH

neutral substance

rain or any other form of precipitation that is unusually acidic ( elevated level of hydrogen ions and pH below 7)

acid rains

keep pH steady and within normal limits in living organisms

- maintains a stable environment by neutralizing small amounts of added acids or bases

buffer

buffers stabilize pH of a solution by taking up excess

hydrogen and hydroxide

water is released as the 2 monomers join

dehydration (synthesis) reaction

water is used to break down macromolecules

hydrolysis reaction

glucose is a

simple monomer

organic compounds composed of C, H, and O in a 1:2:1 ratio

carbohydrates

monomers or building blocks of carbohydrates

monosaccharide/"simple sugars"

main source of energy for cells (cellular respiration)

glucose

formed when 2 monosaccharides are joined via a chemcial bond

disaccharide

long chain of monosaccharides

polysaccharides

a polysaccharides of glucose that animals store in the liver or muscles

glycogen

a polysaccharide of glucose that plants store to use in the winter as their energy source

starch

is a polysaccharide of glucose that plants use as a building block of the cell

cellulose (fiber)

water insoluble molecules made of C, H, O

lipids

fats and oils

triglycerides

made when liquid oils are turned into solid fats, like shortening (banned in the US since 2018)

trans fats

"saturated" with hydrogen atoms

saturated fats

a disease of the arteries characterized by the deposition of plaques of fatty material on their inner walls

atherosclerosis

their chemical structure contains one or more double bonds (typically liquid at room temperature)

unsaturated fats

increase the risk for high blood pressure, heart disease, stroke, diabetes and several cancers (colon)

obesity

super sized portions, fried foods, beverages, and shakes

fast food

essential lipid molecule forming cell membrane

phospholipids

the glycerol head is

hydrophilic which means water loving

the fatty acid tail is

hydrophobic which is water fearing

what do steroids fall under

lipids

steriod hormones are synthesized in our bodys from

cholesterol

what are examples of steroids in our bodies

estrogen and testosterone

what are the building blocks of proteins

amino acids

what are proteins made up of

hydrogen atom (H), amino group (NH2), and a crboxyl group (COOH)

formed when 2 amino acids join to form a dipeptide or a polypeptide

peptide bond

what level of a protein in the linear sequence of amino acids joined by peptide bonds

primary structure

what level of a protein is when 2 or more polypeptides join to form a single protein

quaternary structure

what are proteins often called of the body because they participate in virtually every cellular process

"workhorse"

what are nucleic acids

deoxyribonucleic acid (DNA) and RIbonucleic acid (RNA)