Fundamentals of Biology Flashcards
what atoms does carbon tend to bond with in an organic molecule?
hydrogen
oxygen
nitrogen
__ are molecules that contain more than one element
compounds
strong attractive forces that hold atoms within a molecule
intramolecular forces
force that exists between molecules
intermolecular forces
do intra- or intermolecular forces determine physical properties?
intermolecular
3 varieties of carbohydrates
monosaccharides
disaccharides
polysaccharides
monosaccharides have a ratio of precisely __ to a water molecule, and they have the empirical formula __
1 carbon
(CH2O)n
5-carbon monosaccharides are called
pentoses
6-carbon monosaccharides are called
hexoses
a sugar molecule is alpha if the OH group points __ on 1C
down
a sugar molecule is beta if the OH group points __ on 1c
up
ribose is a
pentose monosaccharides
glucose and fructose are
hexose monosaccharides
glucose and fructose are __ of each other
isomers
what type of reactions bring monosaccharides together?
dehydration/condensation
what functional groups/atoms react in a dehydration/condensation reaction?
hydroxyl (OH) + hydrogen (H)
what is formed in a condensation reaction?
covalent bond
what is released in a condensation reaction?
H2O
what is opposite of condensation/dehydration reaction?
hydrolysis reaction; adds H2O to a covalent bond to split monomers apart
bond between a carbohydrate and another molecule
glycosidic
carbohydrates linked to lipids
glycolipids
carbohydrates linked to proteins
glycoproteins
the disaccharide __ is table sugar
sucrose
disaccharide of glucose and fructose
sucrose
disaccharide of galactose and glucose
lactose
disaccharide of 2 glucoses
maltose
__ may or may not have branching
polysaccharides
uses of polysaccharides
storage
structure
crucial storage polysaccharide in plants
starch
starch contains many __ monomers in linear and branched forms
glucose
linear plant starch
amylose
type of glycosidic bonds in amylose
a-1,4-glycosidic bonds (linear)
branched form of plant starch
amylopectin
type of glycosidic bonds in amylopectin
a-1,4-glycosidic (linear)
a-1,6-glycosidic (branches)
storage polysaccharide found in huans
glycogen
monomers in glycogen
glucose
is amylopectin or glycogen more branched?
glycogen
type of glycosidic bonds in glycogen
a-1,4-glycosidic (linear)
MANY a-1,6-glycosidic (branches)
which type of human tissues store glycogen?
liver (mostly)
muscles
name two a-glucose polysaccharides
starch
glycogen
structural polysaccharide in plant cell walls, wood, and paper
cellulose
cellulose is a __ polymer
glucose
what type of bonds does cellulose contain and what do they do?
b-1,4-glycosidic
allow cellulose to form linear strands that pack together in parallel
intermolecular force that holds adjacent cellulose strands together in parallel
H bonds
structure of cellulose gives it high __
rigidity
can humans digest cellulose?
no - passes thru digestive tract as fiber
chitin is a __ polysaccharide
structural
chitin is found in __
fungal cell walls
insect exoskeletons
chitin is a polysaccharide of __ monomers
N-acetylglucosamine
what type of bonds are in chitin?
b-1,4-glycosidic
chitin looks a lot like __
cellulose
name 2 beta-glucose polysaccharides
cellulose
chitin
protein polymers
polypeptides
polypeptide monomers
amino acid
in an amino acid, what 4 things is the central carbon bonded to?
H
NH2
COOH
R
how many different amino acids?
20
amino acids in a polypeptide are linked by __ covalent bonds
peptide
how do aas form peptide bonds?
dehydration/condensation
what type of reactions separate the aas in a polypeptide?
hydrolysis
a peptide bond is an __ bond involving aas
amide
amide/peptide bonds occur between __ and __ functional groups
NH2
COOH
what enzymes catalyze peptide bond formation?
peptidyl transferases
peptidyl transferases are __ transferases
aminoacyl
polypeptides have an __ and __ terminus
animo (N-)
carboxyl (C-)
primary protein structure
primary
all proteins have __ structure
primary
secondary protein strucutre
3D shape from intermolecular forces between the polypeptide backbone
the __ is the amino acid structural features other than the R-group
polypeptide backbone
does secondary structure include interactions between R-group atoms?
no
which level of protein structure includes alpha helix and beta sheet?
secondary
most common type of intermolecular force for secondary structure
H-bonds
tertiary protein structure
3D protein structure due to non-covalent interactions between aa R-groups
common interactions between R-groups in tertiary strucutre
ionic hydrogen dipole-dipole van der Waal hydrophobic disulfide
“covalent exception in tertiary structure”
disulfide bonds
aas that cause disulfide bond formation
cysteine
quaternary protein structure
3D structure from grouping of 2 or more separate polypeptides
while there are multiple polypeptide chains in quaternary structure, they function as __
1 protein
3 structural classifications of proteins
fibrous
globular
intermediate
solubility of fibrous structural proteins
insoluble
fibrous structural proteins are long polymer __
fibers/sheets
__ form the structural components of cells
fibrous structural proteins
example of fibrous structural protein
collagen
solubility of globular structural proteins
soluble
__ structural proteins are folded tightly and perform many functions
globular
example of globular structural protein
albumin
solubility of intermediate structural proteins
soluble
__ structural proteins are fiber-shaped and perform many functions
intermediate
example of intermediate structural protein
fibrinogen
2 compositional protein classifications
simple
conjugated
simple protein compositions contain only __
amino acids
conjugated protein compositions contain __
amino acids + non-protein components
examples of conjugated proteins
glycoproteins (mucin)
metalloproteins (hemoglobin)
lipoproteins (LDL/HDL)
__ causes proteins to lose their secondary, tertiary, and quaternary structures
protein denaturation
denatured proteins retain their __ structure
primary
loss of __ leads to a loss of protein function
shape
causes of protein denaturation
excess temperature
chemicals
pH change
radiation
__ are molecules that increase reaction rates
catalysts
despite speeding up reactions, catalysts do not affect the __ of a reaction
spontaneity
__ are not used up by the reactions they manipulate; the reaction does not change them
catalysts
catalysts lower __ to speed reactions
activation energies
catalysts do not affect the energy of __ or __
reactants
products
enzymes
biological, globular protein (usually) catalysts
substrates bind to enzymes at the __
active site
are all enzymes proteins
no
ex. ribozymes
active sites have unique properties and __
substrate specificity
measures how efficient an enzyme is in converting substrate to product
specificity constant
enzymes bind at the active site via the __ fit model
induced
non-protein molecules that assist enzymes
cofactors
cofactors usually help enzymes by donating/accepting some reaction component, like __
electrons
what are organic cofactors?
coenzymes
ex. vitamins
inorganic cofactors are usually __
metal ions
enzymes that are bound to their cofactor
holoenzymes
an enzyme that is not bound to its cofactor
apoenzyme
cofactors that tightly/covalently bind to their enzyme are known as __
prosthetic groups
enzyme efficiency is determined by __ and __
temperature
pH
enzyme regulation where inhibitors compete with substrates for active sites
competitive inhibition
we can outcompete a competitive inhibitor by adding more __
substrate
what is enzyme saturation?
all active sites are occupied
when an inhibitor binds to the allosteric site
noncompetitive inhibition
a different location that is not the active site of enzyme catalysis
allosteric site
a noncompetitive inhibitor binding to the allosteric site modifies the __ so that the substrate has reduced binding or cannot bind
active site
enzymes that have both an active site and an allosteric site
allosteric enzymes
a molecule that binds to an enzyme at a site other than the active site and affects its activity
allosteric effector
we cannot __ allosteric inhibitors by adding more substrate
outcompete
the rate of enzyme catalysis is unaffected by increasing the substrate concentration in __
noncompetitive inhibition
substrate concentration at 1/2Vmax
Michaelis Constant (Km)
a __ Km indicates that Vmax is reached at low substrate concentrations
small
a __ Km indicates that Vmax is reached at high substrate concentrations
large
in competitive inhibition, Km is raised but Vmax __
remains the same
in noncompetitive inhibition, Km stays the same but Vmax
is lowered
lipids are __, non-polar molecules
hydrophobic
functions of lipids
store energy
insulation
cell membranes
endocrine lipids
components of a triglyceride
three fatty acid chains attached to a glycerol backbone
specialized fat cells that house triglycerides
adipocytes
triglycerides are produced by __ reactions
dehydration/condensation
which groups of which molecules react to form a triglyceride?
glycerol (H)
what type of bonds exist between glycerol/fatty acids in a triglyceride?
ester
addition of H2O to a triglyceride’s esters will break the fatty acids off the glycerol backbone by a __ reaction
hydrolysis
fatty acids with no double bonds
saturated
saturated fatty acids form __, __ chains
straight
stacked
saturated fatty acids tend to be __ at room temp
solid
fatty acids with 1 or more double bonds
unsaturated
fatty acids with 1 double bond
monounsaturated
fatty acids with 2 or more double bonds
2 or more
cis-unsaturated fatty acids create __ in the fatty acid chain, so…
kinks
they do not pack tightly
cis-unsaturated fats tend to be __ at room temp
liquid
trans-unsaturated fatty acids pack together __, and are very bad for health
tightly
unique type of lipid in cell membranes
phospholipids
components of a phospholipid
2 fatty acids and 1 phosphate group attached to glycerol backbone
amphipathic
having both hydrophobic and hydrophilic properties
ex. phosopholipids
like phospholipids but with a carbohydrate group rather than a phosphate group
glycolipids
cell membranes form through __ of phospholipids
self-assembly
another class of lipid that makes up 30-50% of a eukaryotic cell membrane
cholesterol
cholesterol contains __ hydrocarbon rings and is also amphipathic
four
factors that modulate membrane fluidity
temperature
cholesterol
degree of unsaturation in phospholipid fatty acid tails
what maintains membrane fluidity in the cold?
increasing phospholipid unsaturation
cholesterol
what maintains membrane fluidity in the heat
decreasing phospholipid unsaturation
cholesterol
the __ makes cholesterol, and we can also get it from the __
liver
diet
cholesterol is a precursor to vitamin __ and __ acids
D
bile
__ is a precursor to steroids
cholesterol
general structure of a steroid
fused 4 ring structure - 3 cyclohexanes and 1 cyclopentane
__ are used as hormones and are a structural component of membranes (cholesterol)
steroids
lipids are insoluble and must be transported through the blood by __
lipoproteins
lipoproteins contain a __ of phospholipids, cholesterol, and proteins
coat
lipoproteins contains a __ that contains more cholesterol and triglycerides
lipid core
low-density lipoproteins (LDLs)
have a low density of proteins are are generally considered unhealthy
high-density lipoproteins (HDLs)
have a high density of proteins and are generally considered healthy
waxes and carotenoids are __ derivatives
lipid
esters of fatty acids and monohydroxy alcohols
waxes
waxes are used as a __, protective coating
hydrophobic
carotenoid structure
fatty acid carbon chains with conjugated double bonds and 6-membered rings at each end
carotenoid function
pigments
produce colors in plants and animals
2 common nucleic acids
DNA
RNA
__ have a pentose sugar attached to a nitrogenous base
nucleosides
__ a pentose sugar attached to a nitrogenous base and a single phosphate group
nucleotide
nucleic acids are polymers made of __
nucleotides
nucleoside diphosphate
sugar
base
2 phosphates
nucleoside triphosphate
sugar
base
3 phosphates
4 possible bases of DNA nucleotide
adenine
thymine
cytosine
guanine
4 possible bases of RNA nucleotide
adenine
uracil
cytosine
guanine
purine
base with 2 rings
pyrimidine
base with 1 ring
adenine and guanine have 2 rings and are classified as __
purines
cytosine, uracil, and thymine have 1 ring and are classified as __
pyrimidines
__ nucleotides have ribose sugars with a hydroxyl on the 2’ carbon
RNA
__ nucleotides have deoxyribose sugars without a hydroxyl on the 2’ carbon
DNA
RNA is more reactive than DNA because of its
2’ OH
__ groups attach to the nucleotide sugar at the 5’ C
phosphate
5’ __ of one nucleotide connects to the 3’ __ of another nucleotide in nucleic acids
phosphate
OH
bonding between 5’ phosphate and a 3’ hydroxyl creates a __ bond in nucleic acids
phosphodiester
nucleic acids have __, with a 5’ and 3’ end
directionality
__ add to growing nucleic acid polymers by losing two phosphates (as __)
nucleoside triphosphates
pyrophosphate
DNA manifests as a __, __ helix
antiparallel
double-stranded
A and T (or U) pair via __ hydrogen bonds
2
C and G pair via __ H bonds
3
RNA is usually __ stranded
single
3 fundamental statements of cell theory
all lifeforms have 1 or more cells
cells are the most simple unit of life
cells come from other cells
does cell theory apply to viruses?
no - they are not living cells
central dogma of genetics
information flows from DNA to RNA to proteins
exception to the central dogma are __
prions
prions
mis-folded proteins that cause other proteins to mis-fold
what is the hypothesis for the creation of the first cell as we know it?
RNA world
RNA world hypothesis
self-replicating RNA molecules were the precursor to modern life
2 central facts that support RNA world hypothesis
RNA is able to store genetic info like DNA
RNA is able to catalyze chemical reactions like proteins
