final exam review Q's Flashcards
Which class of large biological molecules do the majority of enzymes belong to?
Proteins
Which is true of enzymes
- they lower Ea
- change the temp of a reaction
- they turn a endergonic reaction into an exergonic one
they lower Ea
What type of pathway and what type of reaction (ex/endo) is photosynthesis
anabolic pathway and endergonic reaction
How do you determine if a reaction is spontaneous
if it is negative
A reaction has a G= -10 kcal/mol, if you double the amount of enzyme, what would G equal now?
-10
A competitive inhibitor decreases the rate of a reaction by
binding to the active site of an enzyme
what is the first law of thermodynamics
energy can’t be created or destroyed
In a biological reaction, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid. Increasing the amount of succinate molecules to those of malonic acid reduces the inhibitory effect of malonic acid. Identify purpose of succinate and fumarate in the reaction.
succinate is the substrate
fumarate is the product
what stage of cellular respiration requires an input of ATP
gylcolysis
which stage of cellular respiration is responsible for making the most ATP
electron transport chain and chemiosmosis
CO2 is released during which of the following stages of cellular respiration
oxidation of pyruvate to acetyl CoA and the citric acid cycle
the oxygen consumed during cellular respiration is involved directly in which process or event
accepting electrons at the end of the electron transport chain
During cellular respiration, what is oxidized / reduced
C6H12O6 is oxidized
O2 is reduced
which stages of cellular respiration make ATP using substrate level phosphorylation
glycolysis and citric acid cycle
During cellular respiration, electrons travel downhill in which sequence
glucose
NADH
electron transport chain
oxygen
during cellular respiration, what directly donates electrons to the electron transport chain at the highest energy level
NADH
What is the effect of increased levels of hydrogen ions in the intermembrane space of the mitochondria
increased ATP production
in a redox reaction, the molecule that loses electrons is
oxidized and reducing agent
when electrons move closer to a more electronegative atom, what happens? The more electronegative atom is
reduced and energy is released
during photosynthesis, CO2 is ____ and O2 is ___?
CO2– reduced
O2– oxidized
How can you tell what wavelength of light is the most effective in driving photosynthesis on a graph
the highest peak
Why is there multiple spectrums of light measured for photosynthesis
there are multiple pigments that can absorb light in addition to chlorophyll a
P680+ is said to be the strongest biological oxidizing agent. Given its functions, why is this necessary
it obtains electrons from the oxygen atom in the water molecule, so it must have a stronger attraction for electrons than what oxygen has
The final electron acceptor associated with photosystem 1 is
NADP
What happens to oxygen produced by the light reactions
it is released into the atmosphere
which of the following are light reaction products of photosynthesis that are utilized in the calvin cycle
ATP and NADPH
Why does chlorophyll look green to the human eye
chlorophyll reflects green light
What occurs in metaphase
aligning of chromosomes in the center of the cell
What occurs in anaphase
separation of sister chromatids
What occurs in prophase
formation of the mitotic spindle
What occurs in prometaphase
fragmentation of nuclear envelope
at what phase of the cell cycle is DNA duplicated
S
what cell cycle checkpoint is responsible for checking if all the DNA has been duplicated
G2
Neurons and some other specialized cells divide infrequently because they
Have entered into G0
Once a cell completes mitosis, molecular division triggers must be turned off. What happens to MPF during mitosis
the cyclin component of MPF is degraded
Is respiration an endothermic or exothermic reaction
exothermic
How do the addition of enzymes impact the change in free energy?
It doesn’t impact it
how does the addition of enzymes impact the activation energy
reduce the amount of energy need and speed up a reaction
How many turns of the calvin cycle does it take to make a G3P molecule
3
Which are a part of the alimentary canal
liver
what is peristalsis
alternative waves of contractions and relaxation of smooth muscles
what is an example of an essential mineral
Ca
what is the first stage of food processing
ingestion
how is saliva involved in digestion
contains amylase, which destroys microorganisms
what is the role of chief cell in the stomach
secrete pepsinogen, an inactive form of the protease, pepsin
region of the cell between the plasma membrane and the nucleus
cytoplasm
region of the cell that ships and receives transport vesicles
golgi apparatus
region of the cell that contains digestive enzymes that break down carbohydrates proteins, proteins, fats, and nucleic acids
lysosomes
which of the following is not true about the endoplasmic reticulum
- the rough er synthesizes phospholipids
- the smooth er synthesizes proteins
- the er is continuous with the nucleus and consists of a network of interconnected tubules
- the smooth er stores calcium in the lumen
the smooth er synthesizes proteins
which is not a part of the endomembrane
- golgi apparatus
- nucleus
- lysosome
- mitochondria
mitochondria
which cellular organelle is involved in Tay-Sachs disease
lysosome
Do chloroplasts/mitochondria have circular DNA
yes
Some of the cells around the alimentary canal must be connected so they are impermeable in water. Which ocell to cell connection is required
tight junctions
the nuclear lamina is composed of
intermediate filaments
what is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell
er
golgi
plasma membrane
which of the following most accurately describes selective permeability
only certain molecules can cross a cell membrane
in a hypotonic solution, what are the water molecules doing
water move into the cell and cause it to burst
phospholipids are ___
- polar
- amphipathic
- hydrophobic
- hydrophilic
amphipathic
which of the following molecules could most easily pass through the cellular membrane via simple diffusion
O2
which of the following would increase the electrochemical gradient across a membrane
a proton pump
some regions of plasma membranes, called liquid rafts, have a higher concentration of cholesterol molecules. At lower temps, these regions
are more fluid than the surrounding membranes
the fluid mosaic model of the membrane proposes that membranes
consist of protein molecules embedded in a fluid bilayer of phospholipids
the membranes of winter wheat are able to remain fluid when it is extremely cold by
increasing the percentage of unsaturated phospholipids in the membrane
what occurs in osmosis
water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration
hypercholesterolemia is a genetically inherited condition that causes individuals to have high levels of LDL in their blood. The cholesterol molecules in LDL will spill out to clog a blood vessel. What type of transport mechanism in impaired in individuals?
receptor mediated endocytosis
why are lipids and proteins free to move laterally in membranes
they are only weak hydrophobic interactions in the interior of the membrane
a molecule moving down its concentration gradient is moving from an area of ____ to ____ concentration
high to low
T/F in humans, there are 8 essential amino acids that the body is able to synthesize on its own
F; the 8 amino acids aren’t able to be synthesized on their own
T/F a goiter is the result of undernutrition
F; result of malnutrition and not getting enough iodine
T/F all cells have organelles
F; they don’t all have membrane bound organelles
T/F all cells have chromosomes
T; they are the genetic information of the cell
T/F all cells have ribosomes
T; all cells must have a site for protein synthesis
what is the purpose of having membrane bound organelles
every organelle has a different purpose, for the cell to properly function in their own unique environment
How would chloroplasts not be able to properly function without membrane compartmentalization
the chloroplasts need their own special environment to be able to function. They have membranes to separate themselves from the cytoplasm and other structures in the cells to enable themselves to convert solar to chemical energy
What type of transport does the potassium channel use
facilitated diffusion bc it is going from H->L conc through a channel protein, not requiring energy
What type of transport does the sodium potassium pump use
sodium potassium pump is active transport that energy because its taking both Na+ and K+ from a L->H conc, requiring energy
What type of transport does the sodium channel use
facilitated diffusion bc it goes from a H->L conc through a channel protein, without energy
what results from equal sharing of electrons between atoms
a nonpolar covalent bond
water is able to create hydrogen bonds with other water molecules due to the partial negative and partial positive charges it possesses. What causes these partial charges
oxygen is more electronegative than hydrogen, meaning the electrons are being pulled towards oxygen
Which element will a hydroxyl group not hydrogen bond with?
- N
- C
- O
- F
C
Which of the following solutions would require the addition of the greatest amount of acid to bring the solution to neutral pH?
- gastric juice at pH
- vinegar at pH
- household bleach at pH 12
- black coffee at pH 5
household bleach at pH 12
definition of a solute?
A substance dissolved in another substance
Which of the following occurs in the transition from liquid water to ice?
Water molecules have more distance between them.
What is the maximum number of hydrogen bonds a single water molecule can form?
4
A container of water of unknown volume is presented to a scientist, who has a thermometer. What can the scientist NOT find?
heat of the water
When the pH of a solution drops ____.
there is a increase in H+ concentration and the solution becomes more acidic
The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why?
The ocean near Portland moderates the temperature.
A covalent chemical bond is one in which ____.
outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals
What is it called when the pH of blood increases and how will the body react to fix this?
Alkalosis: H2CO3 dissociates
Hydrophobic substances such as vegetable oil are _____.
nonpolar substances that repel water molecules
Which of the following statements is true about buffer solutions?
- They maintain a constant pH when bases are added to them but not when acids are added to them.
- They maintain a relatively constant pH when either acids or bases are added to them.
- They maintain a constant pH when acids are added to them but not when bases are added to them.
- They fluctuate in pH when either acids or bases are added to them.
They maintain a relatively constant pH when either acids or bases are added to them.
Which of the following is NOT a property of water?
- Contraction upon freezing
- Cohesive behavior
- Versatility of a solvent
- Ability to moderate temperature
Contraction upon freezing
Which of the following is true of carbon?
- It is highly electronegative.
- It forms only polar molecules.
- It can form a maximum of three covalent bonds with other elements
- It can form both polar and nonpolar bonds.
It can form both polar and nonpolar bonds.
Which of the following statements correctly describes enantiomers?
- They have variations in arrangement around a double bond
- They have an asymmetric carbon that makes them mirror images.
- They have the same chemical properties.
- They have different molecular formulas.
They have an asymmetric carbon that makes them mirror images.
What is NOT a possible characteristic of isomers?
- They can have a different number of atoms
- They have the same molecular formulas
- They can have a different arrangement of bonding of atoms.
- They can be mirror images
They can have a different number of atoms
Which of the following is a hydrocarbon? -H2O -C6H12O6 -C4H10 All are hydrocarbons.
C4H10
hat is valence?
The number of unpaired electrons required to complete an atom’s outermost shell
What is the valence of nitrogen?
3
A disulfide bond is formed between two molecules in a cell. What is the name of the functional group that is likely on both of these molecules that allows for this bond to form?
Sulfhydryl
The formation of a macromolecule, what type of reactionwould join two subunits together?
dehydration reaction
Which of the biological molecules does NOT include polymers?
lipids
Fats contain ____.
Three fatty acids and a glycerol molecule
What type of bond joins two nucleotides together?
Phosphodiester bond
Which nucleotide would you not find in RNA?
Thymine
What component of amino acid structure varies among different amino acids?
the components of the R-group
Tertiary structure can beheld together by ____.
ionic bonds that form between the atoms found in the side chains (R-groups) of the polypeptide
Nucleic acids are made up of these monomers?
Nucleotide
Why might someone argue that silicon based life is possible?
Carbon and silicon both have a valence of 4 and are capable of bonding with CHON the major components of organic molecules
Describe two different problems with silicon based life.
- It is a solid which would be difficult to dispose of silica waste from the organism.
- Silicon is oxidized in one step, releasing a large
- Silicon isomers are rare
Would you expect lactic acid to dissolve in water?
Yes, hydroxyl group and carboxyl group are polar and will form hydrogen bonds with water.
Is this triglyceride saturated or unsaturated? How do you know?
Unsaturated, double bonds present
Are the fatty acids in a cis or trans conformation? How do you know?
Cis-H on the same side of the double bond
