Unit 2 - BioChem Flashcards
covalent bond
sharing of valence electrons
molecule
2+ atoms held together by a covalent bond
compounds
covalent bonds between 2+ different elements
electronegativity
the attraction of an atom for the for the electrons of a covalent bond
non polar covalent bond
the electrons are shared evenly
ionic bond
the attraction for the electron is so unequal between the elements that the atom is stripped away
-formed between a cation and an anion
- cations
- anions
- positive charged ion
- negatively charged ion
hydrogen bond
weak bond formed by a hydrogen already in a polar covalent bond with another highly electronegative atom
O in H2O is more electronegative and therefore has a partial charge
van der Waals forces
non polar molecule
randomly all the electrons move to one side and give it momentary charges on opposite sides
substrate
reacant
most important elements in life
Carbon Hydrogen Oxygen Nitrogen Phosphorus Sulfur
trace elements
elements required by an organism but only in minute quantities
atomic number
of protons or electrons
atomic mass
of protons + # of neutrons
isotopes
same element with different # of neutrons
acid
substance that increases the H ion concentration in a solution
base
reduces H ion concentration
OH- bonds with a H+ and therefore reduces H+ concentration
alkaline - 14 on pH scale
buffers
resist changes in pH
weak acid and its corresponding base
cohesion
water held together by H bonds
important in transport of water against gravity
ex. water evaporates out a leaf and pulls water from the roots up
adhesion
clinging of water to a different substance
specific heat
the amount of heat needed for 1g of the substance to rise 1ºC
evaporization
transformation from liquid to gas
evaporative cooling
the surface of a molecule is left cold because the warm water evaporates (why sweating makes you cool)
solvent
dissolving agent
solute
substance being disolved in
hydrogen shell
each dissolved ion is surrounded by a sphere of water molecules
functional groups
attachments that replace 1 or more hydrogen atoms in the carbon skeleton
go read functional groups flashcards
RN
aldelhyde
carbonyl group is at end of carbon skeleton
ketone
carbonyl group is in the middle of the skeleton
why are carbon atoms so versatile?
make 4 covalent bonds
hydrocarbons
molecules only consisting of carbons and hydrogens
isomers
molecules with same molecular formula but different structures
structural isomers
same molecular formula but different covalent arrangement of atoms
geometris isomers
same covalent arrangement but different spacial arrangment
cis
trans
both geometric isomers
same side of C chain
opposite side
enantiomers
molecules that are mirror images of eachother
carbohydrates
simple sugars and polymers
what do nucleotides consist of?
nitrogen base, pentose sugar, 3 phosphate groups
monosaccharides
- components
- ending
- classified by…
- use
simple sugars
- carboxyl group & hydroxyl groups
- ose
- # of carbons in backbone
- fuel
4 major macromolecules
carbohydrates, lipids, proteins, & nucleic acids
bond that links monomers to become polymers
covalent
condensation / dehydration synthesis reaction
-enzyme used
uses energy to attach new monomer to chain by taking away hydroxyl group from 1 monomer and H from the other to make H2O
-polymerase
hydrolysis
-enzyme used
breaks bonds holding monomers together (H2O required)
-hydralase
use in transporting monomers through cell membrane
enzyme through hydrolysis breaks into monomers which can enter the cell
inside the cell dehydration reactions create polymers
alpha v. beta hydroxyl groups
alpha is a downwards bond
beta is upwards (difficult to hydrolyse)
sucrase
lactase
maltase
enzymes that speed up the hydrolysis of
sucrose, lactose and maltose
chitin
used in exoskeletons of arthopods
lipids
hydrophobic (non polar covalent bonds)
saturated fatty acid
no double C-C bonds (H @ every possible position)
unsaturated
double C=C bond that causes a kink
fat
-use
LIPID - oils are unsaturated and liquid
fat is solid and saturated because takes more heat (nrg) to break them down
-stores energy, cushions vital organs
phospholipids
- hydrophobic
- hydrophilic
2 fatty acids attacked to a glycerol and a phosphate group at the 3rd position
- head (phosphate has - charge)
- tail
phospholipid bilayer
head on outside and tails on inside
-barrier between cell and external environment
proteins
made from 20 different monomers (amino acids)
polypeptide
amino acid
-peptide bond
4 components attached to a central C
- R group (specific to the amino acid)
- H atom
- carboxyl group - CHO2
- amino group NH2
- dehydration reaction removes hydroxyl group and hydrogen
x-ray crystallography
used to determine protein conformation
anti parallel strands
the 2 DNA strands are parallel but go in different directions
polysaccharides
-function
energy storage and building material for the cell
-hydrolyze and break off sugar as needed
starch
-glycogen
storage polysaccharide composed of only glucose monomers (alpha)
-animal starch
cellulose
polysaccharide with alternating alpha beta, making it strong and hard to break
fatty acid
-triglyceride
carboxyl group attached to long carbon skeleton
- 3 fatty acids joined to a glycerol
proteins levels of structure
- primary
- secondary
- tertiary
- quaternary
- sequence of amino acids
- shapes of single strands (coils and folds)
- shape changes based on interactions between R groups
- 2+ strands making shapes
purines v. pyrimidines
-who bonds with who
Purines - 2 rings: A&G
Pyrimidines - 1 ring: C & t & U
-A with T
-G with C
carbohydrates
-produced how
source of energy. polymers and simple sugars
-photosynthesis
metabolism
the total of an organisms chemical reactions
catabolic pathways
release energy by breaking down molecules
anabolic pathways
use energy to make complex molecules
thermodynamics
the study of energy transformations
entropy
measures disorder and randomness
exergonic rxn
net release of free enegry
endergonic rxn
absorbs free enegry
catalyst
changes the rate of a reaction without being consumed in the rxn
cofactors
non protein helpers required by enzymes
coenzymes
organic cofactors
ex. vitamins
inhibitors
prevent enzymes from catalyzing rxns
competitive inhibition
inhibitor binds to active site so substrate can’t
noncompetitive inhibition
inhibitor binds somewhere other than active site causing it to change shape and become inactive
allosteric site
not active site
molecules binding here change the shape of the enzyme - either make it work or not
activators
stabilize the conformation
feedback inhibition
pathway is turned on or off by presence of product or substrate
