Unit 1: Chemistry of Life

what are the 4 most important elements for life?

carbon, hydrogen, oxygen, nitrogen

what is the most important feature of organic chemistry?

carbon’s ability to form 4 covalent bonds

what properties of water are essential to life?

polarity, cohesion, adhesion, surface tension, capillary action, universal solvent, solid less dense than a liquid, specific heat

does catabolism release or require energy?

release

what type of reaction is hydrolysis?

catabolic

does anabolism release or require energy?

require

what type of reaction is dehydration synthesis?

anabolic

does matter flow or cycle?

cycle

does energy flow or cycle?

flow

is attraction between water molecules cohesion or adhesion?

cohesion

is high surface tension a result of cohesion or adhesion?

cohesion

why is water less dense as a solid than as a liquid?

ice has four hydrogen bonds with other water molecules, creating an open crystal structure not present in liquid water

what gives water its special properties?

its hydrogen bonds and polarity

which type of reaction joins two molecules by removing water?

dehydration synthesis

which type of reaction breaks down a molecule by adding water?

hydrolysis

what elements make up carbohydrates?

CHO

what elements make up lipids?

CHO

what elements make up proteins?

CHON

what elements make up nucleic acids?

CHONP

where are the groups attached to a ring located in a ring-structured monosaccharide?

above or below the plane of the ring

what are the main functional groups?

hydroxyl (OH), carbonyl (CO), carboxyl (COOH), phosphate (PO4)

what are the characteristics of the main functional groups?

polar, hydrophilic, found in different kinds of macromolecules, sometimes negatively charged at the pH of a cell

what is glycogen used for?

energy storage for animals

what is starch used for?

energy storage for plants

what is cellulose used for?

structural unit for plants

what is chitin used for?

structural unit for animals and fungi

how are glycosidic bonds formed?

through dehydration synthesis

what is triacylglycerol used for?

energy storage

what is the difference between saturated and unsaturated fatty acids?

unsaturated fatty acids have carbon double bonds and are liquid at room temperature, while saturated fatty acids don’t have carbon double bonds and are solid at room temperature

what do steroids do?

serve as components of cell membranes and chemical messengers

what is the structure of steroids?

a core composed of twenty carbon atoms bonded to form four fused rings with additional functional groups attached

what is the function of phospholipids?

serve as the major components of cell membranes

which parts of the phospholipid are the “tails” and the “head?”

the “tails” are the fatty acids and the “head” is the chemical structure with a phosphate group

what is the main difference between the phospholipid “tails” and “head?”

the “tails” are hydrophobic and the “head” is hydrophilic

are the fatty acid tails on the outside or inside of the cell membrane?

the inside

is the chemical structure with a phosphate group on the inside or outside of the cell membrane?

the outside

what do proteins do?

molecule transport, reception of signals, enzyme catalysis, intercellular joining, and more

what is the amino group made of?

NH2

what is the carboxyl group made of?

COOH

what is the difference between basic and acidic amino acids?

basic are positively charged and acidic are negatively charged

what is the difference between essential and non-essential amino acids?

our body can synthesize non-essential ones but not essential ones, so we have to get the essential ones from food

what is the N terminus?

the free amino group on an amino acid

what is the C terminus?

the carboxyl group on an amino acid

what is the difference between an alpha helix and a beta sheet?

an alpha helix has a twisted polypeptide that forms a helix while a beta sheet has a straight polypeptide that forms a pleated sheet

organic molecules

biological molecules that contain carbon (usually bonded to a hydrogen)

carbon cycle

an intricately linked network of geological and biological processes that shuttles carbon among rocks, soil, ocean, air, and organisms

covalent bond

a pair of electrons are shared between the two atoms

electronegativity

the ability of atoms to attract electrons to themselves

polar covalent bond

electrons are shared unequally between two atoms

nonpolar covalent bond

electrons are shared equally between two atoms

ionic bond

two ions with opposite electrical charges associate with each other because of the differences in charge

chemical reaction

a process by which atoms or molecules are transformed into different molecules

polymers

long chains built from monomers

monomers

smaller repeating subunits that make up polymers

amino acids

the repeating subunits that make up proteins

function of nucleic acids

encode, store, and transmit genetic information

two types of nucleic acids

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

nucleotides

the repeating subunits that make up nucleotides

DNA

the genetic material in all organisms

function of carbohydrates

energy storage and provide structure

monosaccharides

the repeating subunits that make up carbohydrates

lipids

organic molecules that are hydrophobic

hydrophobic

“water fearing” - nonpolar molecules that don’t dissolve in water

hydrophilic

“water loving” - polar molecules that readily associate with and dissolve in water

cohesion

hydrogen bonding between water molecules

adhesion

hydrogen bonding between water and other molecules

high surface tension

extensive hydrogen bonding on the surface of liquid water

why is water less dense as a solid than as a liquid?

ice has four hydrogen bonds with other water molecules, creating an open crystal structure not present in liquid water

specific heat

amount of energy needed to change the temperature of a substance by 1 degree Celsius (extensive hydrogen bonding of liquid water)

why is water a good solvent?

it can form hydrogen bonds with other polar molecules

reactive

participation in chemical reactions that build and break down molecules

solvent

a substance that can dissolve another substance

water is a good solvent for which types of molecules?

polar & organic

dehydration synthesis reaction

two reactants are joined (synthesized) with a covalent bond and water is removed (dehydrated) in the process

hydrolysis reaction

a covalent bond between two molecules is broken by adding water across the bond (hydrolysis = “to break using water”)

monomers of carbohydrates

sugars (monosaccharides)

chemical formula of glucose & fructose

C6H12O6

two structures of monossaccharides

linear and ring/cyclic

isomers

molecules with the same chemical formula but different structures (eg. glucose & fructose)

functional groups

groups of one or more atoms that have particular chemical properties, regardless of what they’re attached to

hydroxyl group

OH; polar, hydrophilic; commonly found in carbohydrates, proteins, and nucleic acids

carbonyl group

CO; polar, hydrophilic; commonly found in carbohydrates and proteins

carboxyl group

COOH; polar, negatively charged at the pH of a cell, hydrophilic, commonly found in fatty acids, amino acids, and proteins

phosphate group

PO4; polar, negatively charged at the pH of a cell, hydrophilic; commonly found in phospholipids, nucleic acids, and ATP

hydrates of carbon

molecules with several CH bonds often paired with a hydroxyl group

how does a linear structure become a ring structure?

the carbon at one end covalently bonds with the oxygen of a hydroxyl group attached to another carbon in the same molecule

disaccharide

two simple sugars covalently bonded together

polysaccharide

three or more simple sugars covalently bonded together (combined in many ways)

complex carbohydrates

long, branched chains of monosaccharides

glycosidic bonds

covalent bonds between monosaccharides or to another polymer of cells

cell membranes (plasma membranes)

structures that define the boundary between the inside and outside of all cells

triacylglycerol

a lipid used for energy storage; major component of animal fat and vegetable oil

structure of triacylglycerol

glycerol joined to three fatty acids

structure of glycerol

three carbon molecule with hydroxyl groups attached to each carbon

structure of a fatty acid

long chain of carbon atoms (hydrogen carbon chain) attached to a carboxyl group at one end

saturated fatty acids

fatty acids without double bonds; solid at room temperature (eg. animal fats)

unsaturated fatty acids

fatty acids with carbon-carbon double bonds; liquid at room temperature (eg. vegetable/fish oils)

van der Waals forces

an interaction of temporarily polarized molecules because of the attraction of opposite charges (only when atoms are very close to one another; weaker than hydrogen bonds)

steroids

components of cell membranes and chemical messengers

structure of steroids

core composed of 20 carbon atoms bonded to form 4 fused rings