biol chp. 2
Monomers
- single molecules that can be linked tighter to form larger molecules - simple sugars -nucleotides
The Miller-Urey experiment demonstrated that
. under specific conditions, the building blocks of life can be formed
Tertiary structure
3D structure
How do enzymes recognizer their substrates?
A binding site that fits the shape and complements the charge of the substrate
Which molecule is used as the primary source of chemical energy for tasks within a cell
ATP
Which of the choices are examples of coupled reactions
ATP hydrolysis drives sucrose synthesis from glucose and fructose, ATP synthesis is driven by a proton gradient formed in the mitochondria
What are the monomers, or building blocks of protein?
Amino acids
IMMUNITY
Antibodies recognize specific pathogens in the body
How does aspirin suppress the inflammation response?
Aspirin binds to the cyclooxyrgenase enzymes, preventing the synthesis of prostaglandins
Aerobic conditions
Citric acid cycle (Krebs cycle) Electron transport chain
TRANSPORT
Cytochromes are election carriers in the electron transport chain
Which of the following is NOT a carbohydrate?
D. Cholesterol
Replication: DNA ->
DNA
Identify hoe NAD+ is used by animal cells during anaerobic respiration
During fermentation, NAD+ is generated from NADH and is used to continue glycolysis
Which of the following statements about metabolic pathways is true?
Each pathway is regulated by specific enzymes.
The electron transport chain uses the transfer of _______ between protein complexes to set up a proton gradient
Electrons
Which statement about thermodynamics is true?
Entropy has a tendency to increase
Which of the statements best describes the overall role of enzymes in metabolism
Enzymes increase the speed of reactions
Endergonic
Generating carbohydrates in photosynthesis, pedaling a bike up a steep hill, constructing DNA from nucleotides
How do these two processes differently affect the metabolism of glucose?
Glucose is produced during photosynthesis to hold the energy gathered from light, whereas glucose is broken down during cellular respiration to release stored cellular energy
Which of the following cellular metabolic processes is active in all cells, regardless of the presence or the absence of oxygen?
Glycolysis
Glycogen
Highly branched, used for energy storage in mice
Which statements describe glycolysis?
It breaks down glucose to two pyruvate molecules It is common to aerobic and anaerobic respiration
What process do mulch cells use if oxygen is not available for aerobic respiration ?
Lactic acid fermentation Glycolysis
Arrange the steps that describe the flow of energy from sunlight to cellular work First step:
Light energy is given off by the sun Chloroplasts of primary producers absorb light energy Light energy, water, and CO2 are used to generate carbohydrates through photosynthesis Carbohydrates are broken down by organisms that consume,e the plant Breakdown of carbohydrates releases chemical energy that can power cellular work Last step
Starch
Moderately branched, used for energy storage in seeds
Compounds that enter the electron transport chain -> Compounds produced by the electron transport chain
NADH, FADH2, O2, ADP -> NAD+, FAD, H2O, ATP
DNA and RNA are nucleic acids. Like other polymers, nucleic acids are made up of repeating units called monomers. What are the monomers, or building blocks, of nucleic acids?
Nucleotides
Anabolic pathway
Photosynthesis generates storage carbohydrates CO2 and H2O, a lipid molecule is constructed from fatty acid subunits
Translation: RNA ->
Protein
Quaternary Structure
Protein-subunit
What product of glycolysis can be subsequently modified to enter the citric acid cycle under aerobic conditions?
Pyruvate
METABOLISM
Pyruvate kinase is a glycolysis enzyme that plays a role in breaking down glucose
RNA molecules that act as catalysts are called
Ribozymes
A plant cell synthesizes cellulose from glucose
Structural support
Choose DNA sequence complementary to AGTC
TCAG
What is a property of phospholipids that explains why lipids self-assemble into a bilayer
The hydrophilic heads of lipids are exposed to water at the membrane's surface
Why does the body use chemical energy?
The potential energy stored in chemical bonds can be released to preform work within a cell
Why does the passage of one glucose molecule through glycolysis have a payoff of only two ATP molecules?
Two ATP molecules are used in the initial phase of glycolysis, reducing the net gain to two ATP
Cellulose
Unbranched, Important for the structure of pine trees
DNA only
Uses thymine and is double stranded
Exergonic
a ball rolling down a hill, breaking down glucose in cellular respiration, metabolizing proteins into amino acids
In the disaccharide sucrose the monomers are held together by a/an
a-1,2 glycosidic linkage
All of the following are true EXCEPT
a. Aspirin is a reversible inhibitor of cyclooxygenase. b. Protein kinases can activate enzymes by adding phosphate groups. c. The binding of an allosteric activator stabilizes the active form of an allosteric enzyme. d. The cancer drug, methotrexate, is an example of a competitive inhibitor. (correct answer is A)
Which of the following statements about ATP is FALSE?
a. The synthesis of ATP is an exergonic reaction.
Not essential for life
abundant and varied food sources, volcanic vents, low levels of carbon dioxide, radiation levels greater than a nuclear explosion
Outputs
amino acids, hydrocarbons
choose the best definition for activation energy
amount of energy required to initiate a chemical reaction
The phospholipid bilayer membrane structure forms in water because the individual phospholipids...
are amphipathic
Retroviruses, such as HIV, have an enzyme that allows them to catalyze DNA synthesis from an RNA template. This evidence supports the hypothesis that
b) early life consisted of an "RNA world."
An inhibitor that binds noncovalently to the active site is ___ while an inhibitor that binds noncovalently to a different site is _____. Both types of inhibition are ____
competitive, noncompetitive, reversible
Breakdown of glucose to pyruvate
cytosol
In an enzyme-catalyzed reaction,
e. The ΔG between reactants and products is not changed.
Lipids are ________
e. insoluble in water
Which stage directly generate the greatest number of ATP molecules per metabolized glucose molecule
electron transport chain and ATP synthase
Anaerobic conditions
fermenation
the nucleotide base that complements cytosine is
guanine
What intermolecular force is responsible for holding the two stranded of a DNA double helix together
hydrogen bond
which process is used to break down polymers into monomers
hydrolysis
Which statements describe a catalyst
increases the rate of endergonic reactions, lowers the activation energy of a chemical reaction, is not consumed during the chemical reaction
DNA
is a single molecule that can be over 10,000,000 nucleotides long, is the genome for eukaryotic organisms, is usually double stranded, includes the base thymine
what is the significance of a lower activation energy
it increases the rate of cellular reaction
STRUCTURAL
keratins are fibrous proteins that are components of skin and hair.
AEROBIC
oxygen as final electron acceptor high levels of ATP produced Oxygen required acetyl CoA production Complete combustion of glucose
Which of the statements regarding potential energy is true
potential energy is the energy that an object has based on its position
ANEROBIC
small organic compounds as final electron acceptor low levels of ATP produced oxygen not required fermentation oxygen toxicity ethanol production
How does the second law of thermodynamics apply to this process
some energy does work and some energy escapes as thermal energy when the energy in ATP is released from the chemical bond
The ATP made during glycolysis is generated by
substrate-level phosphorylation
Product
the small chains of simple sugars
Enzyme
the specialized protein
Substrate
the starch molecules
Where should the drug bind to competitively inhibit the enzyme?
to the active site of the enzyme
Pyruvate is a product of glycolysis and is subsequently converted to acetyl-CoA. Acetyl-CoA is a substrate for the citric acid cycle (CAC) Exactly how many molecules of glucose must be oxidized in glycolysis to provide the input for four turns of the CAC?
two
Polymers
- molecules composed of smaller sub units linked together -starch - muscle protein - RNA
a helices
-coil- like structure around a central axis -form lond, thin structures important for transmembrane proteins
How does dehydration reaction differ from a hydrolysis reaction
-dehydration removes a water molecule and hydrolysis adds a water molecule -polymers break into monomers in hydrolysis and monomers join together in dehydration
B sheets
-keep their shape due to hydrogen bonds between adjacent polypeptide chains - flat, zig-zag-like structure
What is a phosphodiester bond
A covalent bond that forms the backbone of DNA and RNA molecules
what is the proton gradient in cellular respiration?
A higher concentration of protons (H+) on one side of a membrane than the other
Arrange the steps of ATP generation by ATP synthase in the order that they occur First step
A hydrogen ion gradient is established between the inter membrane space and the mitochondrial matrix hydrogen ions move down their gradient through a channel in ATP synthase Hydrogen ions cause the rotor portion of ATP synthase to spin Catalytic sites in the knob portion of ATP synthase phosphorylate ADP Last step
Which statement is an example of the chemical potential energy in adenosine triphosphate (ATP) being turned into work
A phosphate group is transferred from ATP to glucose during glycolysis, ATP hydrolysis induces a conformational change in a protein that moves ions across a membrane
How do enzymes lower the activation energy of a reaction?
By stressing a bond in a substrate that needs to be broken, by forming a temporary bond between the active site and the substrate, by producing conditions within the active site conducive to the reaction
Which equation is the simplified chemical equation for cellular respiration?
C 6 H 12 0 6 + 6 0 2 -> 6 H 2 O +6 C O 2
Which is the molecular formula for carbohydrate
C4H8O4
A liver cell synthesizes glycogen from glucose
Energy storage
Which of the environment factors listed can cause denaturation?
Extreme pH, excessive heat
A proton gradient is formed in the mitochondria such that the concentration of proton (H+) is higher on one side of the inner mitochondrial membrane than on the other side What is the purpose of this proton gradient?
Generated ATP in the electron transport chain
Which of the statements is a simplified equation for cellular respiration? Glucose + Oxygen -> Carbon dioxide + water Glucose + nitrogen -> Carbon monoxide + water Carbon dioxide + water + light -> glucose + oxygen Protein + water -> amino acids + carbon dioxide
Glucose + oxygen -> carbon dioxide + water
Catabolic pathwy
Glycolysis converts one molecule of glucose to two molecules of pyruvate, A protein molecule is broken down into amino acid subunits
Which describes how cofactors and coenzymes affect the function of enzymes? Decrease catalytic function Increase catalytic function increase or decrease catalytic function Do not impact catalytic function
Increase catalytic function
What is the function of the proton gradient in the mitochondrion?
It is potential energy that the cell uses to generate ATP
Why is cellular respiration referred to as an aerobic process?
It requires oxygen to occur
Reduction
Loss of Oxygen gain of electrons gain of hydrogen decrease in the number of carbon-oxygen bonds
Oxidation
Loss of electrons loss of hydrogen increase in the number of carbon-oxygen bonds gain of oxygen
A heart cell uses the energy in glucose to synthesize ATP
Metabolism for energy
Conversion of pyruvate to acetyl-CoA
Mitochondrial matrix
SIGNALING
Mitogen-activated protein (MAP0 kinases direct a cell's response to stimuli, such as osmotic stress
During glycolysis, glucose is broken down into two molecules of pyretic acid. How many carbon atoms are in each pyruvic acid molecule?
Number of carbon atoms: 3
Transcription: DNA ->
RNA
How do organisms use energy, according to the first law of thermodynamics
The light energy collected during photosynthesis is converted to chemical energy , animals eat to obtain chemical energy that they convert into kinetic energy
Choose all the true statements about oxidative phosphorylation
The oxidation of NADH provides enough energy to produce three ATP molecules During oxidative phosphorylation, the proton motive force created by the electron transport chain drives the production of ATP Oxidative phosphorylation is an aerobic process
Feedback inhibition is important for the regulation of Manu metabolic pathways. Which of the statements are examples of feedback inhibition?
The production of tryptophan is halted by the presence of excess tryptophan The beginning of glycolysis is inhibited. by high levels of ATP
Which definition describes enthalpy
a measure of the amount of internal energy in a system at constant pressure
Which of the statements best describes a protocol
a membranous sac containing organic molecules that interact with one another
which statements describe a chemical reaction
a molecule breaks apart, an acid is neutralized by a base
Which of these describes an anabolic pathway
a pathway that generates molecules from smaller subunits
What is a statement that describes a gene
a section of DNA in which the code for a protein is located
The role of oxygen gas in our cells is to
accept electrons from the respiratory chain
the nucleotide base that complements thymine is
adenine
A ribozyme is
an RNA catalyst
The "backbone" of a nucleic acid molecule is made of
b. alternating sugar and phosphate groups
Consider the following double-stranded DNA region: 5′ -TGCCAT-3′ 3′ -ACGGTA-5′ If the lower strand is transcribed, which of the following strands will result?
c. UGCCAU
What would happen to the value of ∆G for the reaction in which phosphoenolpyruvate is converted to pyruvate (∆G = -23 kJ/mol) when it reaches equilibrium?
d. ∆G would equal 0.
When cells link monomers together to construct polymers, which process is used to make the monomers form bonds with each other?
dehydration
the active site of an enzyme
determines, by its structure, the specificity of the enzyme
What is the share of DNA molecules
double helical
What is the shape of DNA molecules?
double helictal
when do amino acids that have had their amine groups removed enter the pathways of cellular respiration?
during glycolysis or during the Krebs cycle
Choose from the list below the correct numbers of ATP molecules released per glucose molecule by glycolysis (gly), the citric acid cycle (CAC), and oxidative phosporylation (OP)
gly 2 (net); CAC 2; OP 28
Both Aerobic and Anaerobic conditions
glycolysis
If ΔG of a chemical reaction is negative and the change in entropy is positive, you can conclude that the reaction
is exergonic
RNA
is usually single stranded, includes ribose sugar, can be translated into protein, is a single molecule that can form a complex secondary structure
Essential for life
liquid water, sunlight, chemical reaction, or geologic heat providing energy, atoms and molecules from which to build living cells
Secondary structure
local hydrogen-bond pattern
which characteristics of ribozymes provide support for the RNA world hypothesis
made of RNA, involved in protein synthesis, are catalysts
Both RNA and DNA
made of nucleotides, Fontaine's codes for proteins
citric acid cycle
mitochondrial matrix
the majority of ATP is generated
mitochondrial membrane
Compared to fermentation, the aerobic pathways of glucose metabolism produce
more ATP
DNA and RNA are nucleic acids. Like other polymers, nucleic acids are made up of repeating units called monomers
nucleotides
DNA and RNA are nucleic acids. Like other polymers, nucleic acids are made up of repeating units called monomers. What are the monomers, or building blocks, of nucleic acids?
nucleotides
Most of the ATP produced during cellular respiration comes from
oxidative phosphorylation
The oxidation of malate to oxaloacetate is coupled to the reduction of NAD+ to NADH + H+. In this process, NAD+ is a(n)
oxidizing agent
Which statement describes a functional group?
part of a larger molecule that can participate in a chemical reaction
Primary structure
polypeptide chain
Anabolic reactions
require an input of energy
Cheese, which is a solid at room temperature, is often used in cooking
saturated
Coconut oil, which is a solid at room temperature, can be used as an alternative to butter
saturated
Which substances contain, or are examples of , lipids
testosterone, beeswax, cell membrane
What describes a genome
the collection of genetic material in a cell or organism
choose the best description of kinetic energy
the energy an object has due to its motion
How does adenosine triphosphate (ATP) drive energy-required reactions in the cell
the hydrolysis of ATP is coupled to a non-spontaneous reaction
which statement explains the appearance of a three-layer membrane in micrographs
the hydrophilic heads of the bilayer show up as two dense layers, whereas the hydrophobic tails show up as a single, lighter layer
Olive oil, which is a liquid at room temperature, is used in cooking pasta
unsaturated
The oil inside fish oil supplements is fluid at room temperature
unsaturated
all of the following nitrogenous bases are found in DNA except
uracil
which statement best describes free energy
useful energy, associated with a reaction, that can perform work
RNA only
uses uracil, single stranded
Inputs
water, ammonia, hydrogen gas