Bio unit 2 test

what are cells mostly made up of

water

what is one of the most important element in cells

carbon

what organic molecules is carbon a "backbone" for

proteins
lipids
carbohydrates
nucleic acids

what are hydrocarbons

organic molecules consisting of only carbon and hydrogen

what are functional groups

certain groups of atoms attached to carbon skeletons of different molecules that give the molecules their properties

hydrogen and oxygen bonded
makes molecules alcohols
are polar
attract water molecules and dissolves organic compounds

hydroxyl

what are organic compounds made of/ have

carbon

carbon and oxygen double bonded
has two types: aldehydes and ketones
determine overall structure of molecules and make molecules polar

carbonyl

makes a substance acidic
critical in creating bonds between molecules

carboxyl

NH2
gives molecules a slightly positive charge

amino functional groups

what are amino acids made of

a central carbon attached to an amino group, hydrogen atom, carboxyl group, variant r

SH
critical in binding to other groups in amino acid chains
help determine the structure of 3D proteins

sulfhydryl

PO
critical in binding to other groups and saving energy in the chemical bonds formed
critical in the structure of ATP

phosphate groups

macromolecules

large molecules composed of thousands of covalently connected atoms

monomer

single "building block" of organic molecules

polymer

many monomers bonded together

which of life's organic molecules are polymers?

carbohydrates
proteins
nucleic acids

how do monomers connect together?

dehydration synthesis

how are polymers disassembled into monomers?

hydrolysis

what is a product of dehydration synthesis?

water

what is needed to perform hydrolysis?

water

sugars and the polymers of sugars

carbohydrates

simplest carbohydrates

monosaccharides

carbohydrate macromolecules are...

polysaccharides

what are polysaccharides important for?

energy carrying
structure

starch

energy storage polysaccharide of plants
consists entirely of glucose monomers

glycogen

energy storage polysaccharide in animals
mainly in liver and muscle cells

cellulose

structural polysaccharide forming the tough wall of plant cells

polymers with alpha glucose

helical

polymers with beta glucose

straight

mammals can digest

alpha linkages but not beta linkages

structural polysaccharide found in the exoskeleton of arthropods and cell walls of fungi

chitin

the one class of large biological molecules that do not form polymers

lipids

all lipids are...

hydrophobic

three important lipids

fats (triglycerides)
phospholipids
steroids

constructed of two types of smaller molecules: glycerol (tree carbon alcohol with a hydroxyl group attached to each carbon) and fatty acids (carboxyl group attached to a long carbon skeleton)

fats

fatty acids vary by

length
number and locations of double bonds

most animal fats are... which are solid at room temperature

saturated fats

plant and fish fats are usually... and liquid at room temperature

unsaturated

two fatty acids and a phosphate group are attached to glycerol

phospholipids

fatty acid tails are...

hydrophobic

head is...

hydrophillic

when phospholipids are added to water, they form a ... with hydrophobic tails pointing toward the ... which can be found in cell membranes

bilayer/ interior

lipids characterized by a carbon skeleton consisting of four fused rings (3 6-carbon and 1 5-carbon)

steroids

an important steroid that is a component in animal cell membranes

cholesterol

account for more than 50% of the dry mass of most cells and do everything

proteins

polymers of amino acids

polypeptides

one or more polypeptides

protein

amino acids are...

proteins

amino acids are linked together into a polypeptide by

peptide bonds

the sequence of amino acids determines its ... and therefore its ...

shape/function

primary structure

unique sequence of amino acids

secondary struture

coils and folds in the polypeptide chain

tertiary structure

interactions between various side chains (r groups)

quaternary structure

when a protein consists of multiple polypeptide chains

typical secondary structures

alpha helix coil
beta pleated sheet

a slight change in primary structure can affect...

a protein's conformation and ability to function

enzymes

proteins that act as catalysts that speeds up chemical reactions and perform their function repeatedly

when a protein has lost its 3D confirmation it becomes ... (can be affected by changes in pH, salt concentration, and temp)

denatured

two types of nucleic acids

DNA and RNA

provides directions for its own replicatin

DNA

DNA directs synthesis of ... and controls protein synthesis

mRNA

protein synthesis occurs in...

ribosomes

made of a nitrogenous base, a pentose sugar, and a phosphate group

nucleotide monomers

portion of nucleotide without the phosphate group

nucleoside

polynucleotide

nucleotide polymers are linked together

2 polynucleotides form a double helix in

DNA

elements essential to life

carbon
oxygen
hydrogen
nitrogen
(CHON)

when does a hydrogen bond form?

when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom

van der walls interactions

molecules or atoms that are very close together can be attracted by fleeting charge differences

the main reason earth is habitable

water

water is a ... molecule (opposite ends have opposite charges)

polar

cohesion

hydrogen bonds hold water molecules together

high specific heat

water can absorb or release a lot of energy without large changes in its temperature

when bonds break heat is ...

absorbed

when bonds form heat is...

released

evaporative cooling

as liquid evaporates, the remaining surface cools

water has a ... heat of vaporization

high

why does ice float in liquid water

hydrogen bonds in ice are more "ordered", making it less dense

universal solvent

can dissolve many substances due to its polarity
makes aqueous solutions

why is water an effective solvent?

it readily forms hydrogen bonds

t/f water can dissolve compounds made of nonionic polar molecules

true

free energy

the portion of a system's energy that can do work when temperature and pressure are uniform throughout

catalyst

chemical agent that speeds up a reaction without being consumed by it

an enzyme is a ...

protein

enzymes end in

-ase

activation energy

the amount of energy a chemical reaction needs to get started (usually in the form of heat)

how do enzymes catalyze reactions?

they lower the activation energy needed

do/do not affect to change in energy

do not (hasten reactions that would occur eventually)

substrate

the reactant that the enzyme acts on

what is formed when the enzyme bonds to its substrate?

the enzyme-substrate complex

active site

where the substrate binds to the enzyme

induced fit

how the enzyme folds around the substrate (like a handshake)

how do enzymes lower activation energy?

orienting substrates correctly
straining substrate bonds
providing favorable microenvironment
covalently bonding to the substrate

enzyme activity can be affected by...

environmental factors (pH and temp)
chemicals that specifically influence the enzyme

each enzyme has...

an optimal temp/pH

enzymes at high temperatures are...

denatured

enzymes at low temperatures are...

inactive

inhibitors

can slow enzyme activity

competitive inhibitors

bond to active site of the enzyme