ch 2 Flashcards
everything is built from _____
atoms
different types of atoms create different _______
elements
valance electrons
electrons in outermost shell
covalent bond
share electrons
define chemical reactions
atoms form or break bonds
reactants become products
covalent bonds can be ______
single
double
triple
polar covalent bond
uneven sharing of electrons
nonpolar covalent bond
even sharing of electrons
define electronegativity
atom’s tendency to attract electrons
hydrogen bonds
intermolecular interaction
DNA and proteins
are nonpolar molecules hydrophobic or hydrophilic
hydrophobic
reactions depend on things like
concentration
pH
temperature
Gibbs free energy
molecules react to go from ______ to __________
high energy to low energy
define exergonic
reaction that releases energy
favorable
define endergonic
reaction that needs energy
unfavorable
what is reaction coupling
combines favorable and unfavorable reactions, to make the whole thing favorable
what is the body’s main energy molecule
ATP
define macromolecules
large molecules
macromolecule functions
energy
structural
information storage
define oligomers
small polymers, less than 10 monomers in length
what shapes are carbohydrate monomers found in
linear or ringed
functions of carbohydrates
storing energy
building biological structures
cell recognition
glycocalyx
polysaccharide projections on cell surface
function of the glycocalyx
cells read information in other cells glycocalyx to identify each other
are lipids polar or nonpolar
nonpolar
what is the main type of lipid
fatty acid
how does the body store fatty acids
triglycerides
define amphipathic
one polar and one nonpolar region
cholesterol is a ____
lipid
steroid hormones are ______
lipids
nucleotides consist of
phosphate
sugar
base
what are the purine nucleotide bases
adenine and guanine
double ringed
what are the pyrimidine nucleotide bases
cytosine, thymine, uracil
single ringed
define oligonucleotides
polymers 2-10 in length
how many different amino acids are there
20
nonpolar amino acids
H + C
no charge
polar amino acids
O +N
charged
basic amino acids
positive charge
acidic amino acids
negative charge
define disulfide bond
helps protein fold
define substrate
enzyme’s reactant
define active site on a enzyme
where the substrate binds to the enzyme
define induced fit
enzyme alters substrates shape to match transition state
easier to move past transition state
define direct catalysis
enzyme forms temporary covalent bonds with substrate
modifies substrate towards product
define cofactor
molecules used to assist catalysts
binds on active site alongside substrate
what are the three main subtypes of cofactors
ionic cofactors
coenzymes
prosthetic groups
define ionic cofactors
metal ions that bind active site alongside substrate and assist catalysis
define coenzyme
small organic molecules used by enzymes during reactions
ex. NADH
define prosthetic groups
organic molecules tightly bound in enzyme
constant part of enzyme and cannot freely leave
T or F: Cells can activate or inactivate ensymes
true
define competitive inhibition
inhibitory molecule binds and blocks active site
prevents substrate from binding and inactivates enzyme
define allosteric regulation
regulatory molecule binds at allosteric site and it changes active site shape
define feedback inhibition
enzyme is regulated by its own product
proteins are bound in ____________
macromolecule complexes
define post-translational modifications
chemical alterations to a protein to change its function
