How many electrons fill carbon's valence shell
How to determine which solution has the lowest concentration of hydrogen ions (H+)
have the lowest pH level
Imagine: atomic properties altered of hydrogen and oxygen atoms, two atoms equal in electronegativity, what changes?
adhesion, cohesion, surface tension
Water at its densest
Nitrogen (N) has much more electronegativity than Hydrogen (H), what is true about ammonia NH3?
Each hydrogen bond has a partial positive charge
state in which the rate of the forward reaction, the state in which the rate of the forward reaction equals the rate of the forward reaction equals the rate of the reverse reaction and products do not change
Weak acid, acetic acid (CH3COOH) can form a buffered solution, weak acids buffers bc
acetic acid partially dissociates (ionizes) in water to form protons (H+) and conjugate base (CH3COO-) when this happens, the free protons and conjugate base are available to neutralize incoming OH- and H+
sharing single electrons between atoms
MgCl2 form crystals when bonded
sharing of electrons between atoms
slight negative charge at one end of one water molecule attracted to slight positive charge another water molecule – H of one water molecule and the O of another water molecule – gives rise to cohesiveness of water molecules
maintain relatively constant pH when either acids or bases added
amount of energy required to raise temperature of 1 g of water by 1 C; amount of heat energy that 1 g of water releases when it cools 1 C
differ in covalent arrangements of their atoms
they have variations in arrangement around a double bond
Polar covalent bonds
unequal sharing electrons
Polar covalent bond
oxygen 3.5 electronegativity, phosphorus electronegativity 2.2
hydroxal functional group
forms hydrogen bonds with oxygen and helps dissolve compounds
sugars with ketone groups
Amino functional group
Amino functional group
Acts as base
Can donate H+
Stabalize protein structures
Confers on a molecule the ability to react with water, release energy
Affects shape and function male and female sex hormones
Affects expression genes on DNA
How would you mimic the function of a molecule in a lab?
Investigate the 3D shape of the naturally occurring molecule to determine what elements of its structure are central and design the molecule similar to the chemical structure
Non polar covalent bond
two atoms equally electronegative form
mirror images of each other
4 elements make up most of life's matter
carbon, hydrogen, nitrogen, oxygen
indicates number of protons
sum of protons and neutrons in atom's nucleus
number proteins and neutrons in nucleus
Water has a high specific heat because
They absorb and release heat when hydrogen bonds break and reform
Ice floats in water because
Hydrogen bonds stabilize and keep molecules of ice farther apart than the water molecules of liquid water
Why are hydrocarbons insoluble?
They exhibit molecular complexity and diversity
Compound contains hydroxyl group predominant functional group so
should dissolve in water
two functional groups always found in carboxyl and amino
Testosterome and estradoil have different functional groups attached to same
Common ancestry of life
ubiquitous use of catalysts by living organisms
Each element unique and different from others in chemical properties by
unique number of protons in nucleus
The presence or absence of double bonds between carbon atoms and others determine if carbon's covalent bonds are
tetrahedral or planar
Colum periodic table
elements have the same number of electrons in shell
same number of protons but different number of electrons, differing in atomic mass
If a pH solution decreased from 9 to 8
concentration of H+ increased tenfold and concentration of OH- decreased one tenth
What is the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers, hydrolysis breaks them apart
How might a change of an amino acid at a site, distant from the active site of an enzyme alter an enzyme's substrate activity?
By changing the enzyme's ability
Lactose, sugar in milk, composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. What is it classified as?
What is not embedded in hydrophic portion of the lipid bi layer?
Nitrogenous base and a sugar
Molecules that pass through the cell membrane most easily
small and hydrophobic
Cell equilibrium with environment, this occurs for substances that can diffuse through the cell
Random movement of substances in and out of the cell
Bacterium engulfed by a white blood cell through the phagocytes digested by enzymes in this
Difference between DNA and RNA
DNA nucleotides contain different sugar than the RNA
What is the pathway taken by the newly synthesized protein pathway that is secreted by the cell
ER -> Golgi -> vesicles that fuse with plasma membrane
insoluble in water
Fluid mosaic model proposed
the cell membrane consists of protein molecules embedded in fluid bi-layer of phospholipids
NOT component of each monomer to make proteins
Phosphorus atom, P
Force driving simple diffusion _ while energy source for active transport is _
concentration gradient; ATP
Large numbers of ribosomes present in cells that specialize in producing
Induced fit hypothesis of enzyme catalysis
Binding of the substrate changes shape of the enzyme's active site
There is more solute inside the cell than in the solution surrounding the cell. As a result, there is more water molecules (solvent) surrounding the cell than water molecules inside the cell.
There is more solute in the solution surrounding a cell than inside, resulting in a greater amount of water (solvent) inside the cell. The more solute, the less solvent (i.e. water).
molecule binds outside of active site and allosterically decreases enzyme's affinity for substrate
Primary role of oxygen in cellular respiration
acts as an acceptor for electrons and hydrogen, forming water
Primary function of the Calvin cycle?
synthesize simple sugars from carbon dioxide
the cellular process of breaking down large molecules into smaller ones
They consume energy to build up polymers from monomers.
types of reactions would decrease the entropy within a cell
The active site of an enzyme is the region that
is involved in the catalytic reaction of the enzyme.
According to the induced fit hypothesis of enzyme catalysis, which of the following is correct
The binding of the substrate changes the shape of the enzyme's active site.
Competitive inhibitors block the entry of substrate into the active site of an enzyme. On which of the following properties of an active site does this primarily depend?
the ability of an enzyme to form a template for holding and joining molecules
metabolic pathways that release stored energy by breaking down complex molecules
When electrons move closer to a more electronegative atom, what happens
Energy is released
The more electronegative atom is reduced.
The ATP made during glycolysis is generated by
takes up most of the volume of the plant
Glysosidic linkage is analogous to
a peptide bond
Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some cancer. Cancer cells given this drug are unable to
Seperate chromosomes during division
The R-group, or side chain, of amino acid serine -CH2-OH. R group of amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find these amino acids in a globular protein in aqueous solution?
Leucine would be on the interior, serine would be on the exterior
Mechanism in which the end product of metabolic pathway inhibits an earlier step in pathway –
Cell has enzymes, DNA, ribosomes, plasma membrane, and mitochondria, what is it?
Nearly any eukaryotic organism
Catabolism is to anabolism as _ is to _
Passive process in which molecules move from a higher concentration to a region of lower
Cell size is limited by
surface to volume ratio
The extracellular matrix is thought to participate in regular of animal cell behavior by communicating information from outside to the inside of the cell via
5’ end of a polynucleotide strand RNA
5’ end has a phosphate group attached to number 5 carbon ribose
Sodium potassium pump
Moves three sodium ions out of a cell and two potassium ions into a cell while consuming 1 ATP
Allosteric enzyme regulation associated with
An enzyme with more than one subunit
When ATP releases some energy, it also releases inorganic phosphate. What happens to inorganic phosphate in cell?
May be used to form a phosphorylated intermediate
Ions diffuse across membranes through specific ion channels down
Their electrochemical gradients
ATP important molecule in metabolism bc
Provides energy coupling between exergonic and endergonic reactions
In receptor mediated endocytosis , receptor molecules initially project outside the cell. Where do they end up?
On the inside surface of vesicle
Polysaccharide important component in structure animal and fungi?
Not part of a prokaryotic cell
Involves the decrease in entropy?
In fractionation of homogenized cells using centrifugation, primary factor determines whether a specific cellular component ends up in supernatant or palette is
Size and weight component
This is abundant in liver cells
Nuclear lamina is an array of filaments on inner side of nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would be the immediate consequence?
Change in the shape of the nucleus
Humans cannot digest cellulose because
Humans have enzymes that can hydrolyze the glyosidic linkages of starch but not glyosidic linkages of cellulose
Water moves across a membrane from areas of lower solute concentration to areas of higher concentration
If you disrupt all hydrogen bonds in a protein. What level structure is preserved?
Common to plant and animal cells
net input of energy from its surroundings is required for the reaction
consume energy to build up polymers from monomers
Phospholipids and triglycerides both
Have a glycerol backbone
Bacterium, you find the DNA in
How many molecules of water are used to completely hydrolyze a polymer that is 11 monomers long?
Occurs regardless if oxygen is present
Process in eukaryotic cells will proceed normally whether oxygen is present or absent
Consits two sister chromatids joined by a centromere
During the duration of meiosis 1, each chromosome
consists of two sister chromatids joined by a centromere
Oxidizing agent in:
Pyruvate + NADH + H+ -> lactate + NAD+
Glycolysis takes place in
Lactic ACid Cycle
mitochonria inner membrane
Glycolysis net product is
Kreb net product
1 ATP per 2 pyruvate
Synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient
Immediate (most proximal ATP synthesis) energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation
H+ concentration across membrane holding atp synthase
Inside active Mitochondrion, most electrons follow which pathway
Citric acid cycle – NADH – electron transport chain complexes – oxygen
For anaphase to begin, what must occur?
Cohesion must be cleaved enzymatically
G1 S G2 M
Sister chromatids separate during
Mitosis and Meiosis II
What phase do centrioles begin to move apart in animal cells
Following intermediary metabolites enters citric acid cycle and is formed, in part, by removal of carbon from one molecule pyruvate
Glyceraldehydes 3 phosphate
Complete set of an organisms genes and other DNA sequences
In alcohol fermentation NAD+ regenerated from NADH by
Reduction acetaldehyde to ethanol
Maintained at constant levels through cell cycle requires cyclin become catalytically active
complete complete set of chromosomes
( 2 sets )
half of the chromosomes
( 1 set )
Helicase in Replication
unzip helix and forms replication bubble
DNA polymerase 1
remove DNA primers and adds new DNA
(produces DNA in opposite orientation of stand)
builds primer complementary DNA template
SSBP (single strand binding protein)
bind 2 unzipped strands and keep them seperate
DNA polymerase 3
produces nucleic acid in leading strand
primer and DNA
Monomers for the synthesis of DNA
Anti parallel strands of nucleotide that form the DNA double helix are held together by
hydrogen bonds between nitrogenous bases
Information in DNA contained in
the sequence of nucleotides along the length of the two strands of the DNA molecule
Role DNA polyermerase in DNA replication
attach free nucleotides to new DNA strand
DNA polymerase adds nucleotides to the __________ of the leading strands, and to the __________ of the lagging strands (Okazaki fragments)
Enzyme joins Okasaki fragments
After the formation of a replication bubble, which of the following is the correct sequence of enzymes used for the synthesis of the lagging DNA strand
helicase, primase, DNA polymerase, ligase
The removal of the RNA primer and addition of DNA nucleotides to the 3' end of Okazaki fragments in its place is carried out by __________
DNA polymerase I
The unwinding of DNA at the replication fork causes twisting and strain in the DNA ahead of the fork, which is relieved by an enzyme called __________
Once the DNA at the replication fork is unwound by helicases, what prevents the two strands from coming back together to re-form a double helix?
Single-strand binding proteins bind the unwound DNA and prevent the double helix from re-forming.
Which set of enzymes is involved in nucleotide excision repair?
nuclease, DNA polymerase, and ligase
get shorter with each round of DNA replication
is an enzyme that lengthens telomeres
In the "beads on a string" structure of unfolded chromatin, the "beads" are __________.