Final Exam -- Old tests Flashcards
(99 cards)
1
Q
T/F: The movement of a solute against a concentration gradient is called active transport.
A
True
2
Q
T/F: An organelle that is semi-autonomous can grow and divide independently.
A
False
3
Q
T/F: Phospholipids can flip-flop across the membrane spontaneously; the process does not require the input o energy or enzyme activity.
A
False
4
Q
T/F: Signal transduction is the process by which cells transmit signals from inside the cell to the outside.
A
False
5
Q
T/F: Facilitated diffusion si the movement down a gradient with the aid of a transport protein.
A
True
6
Q
T/F: A reaction with a delta G > 0 is endergonic and requires a net input of energy to proceed.
A
True
7
Q
T/F: Micelles are spherical structures that are formed spontaneously from amphipathic phospholipids in an aqueous environment.
A
True
8
Q
T/F: A molecule that has been reduced has gained electrons and a hydrogen atom
A
True
9
Q
T/F: Polar amino acids tend to be found on the surface of soluble proteins
A
True
10
Q
T/F: Functional groups such as sulfhydryl and phosphate groups are nonpolar and will not interact with water.
A
False
11
Q
T/F: Both covalent and noncovalent interactions are needed to stabilize proteins.
A
True
12
Q
T/F: Denaturation causes proteins to unfold and results in enhanced function
A
False
13
Q
Which of the following is NOT soluble in water?
- Lipids
- sugars
- amino acids
- disaccharides
- nucleic acid
A
Lipids
14
Q
What kinds of bonds stabilize the formation of an alpha helix within a polypeptide?
- hydrogen bonds
- covalent bonds
- ionic bonds
- peptide bonds
- disulfide bonds
A
hydrogen bonds
15
Q
Triglycerides are _____.
- carbohydrates
- nucleotides
- proteins
- lipids
- amino acids
A
lipids
16
Q
The Anfinsen experiment showed that three-dimensional structure of a polypeptide is:
- unaffected by harsh conditions
- important for neutralizing pH
- encoded in the amino acid sequence
- determined by covalent interactions
- None of these are true
A
encoded in the amino acid sequence
17
Q
Delta G for the following reaction is +686 kcal/mol:
C6H12O6 + 6O2 –> 6CO2 + 6H2O
This means that:
- The reaction is exergonic
- Energy is taken up from the surroundings
- There is no net charge in the energy content of the molecules
- Energy is needed to start the reaction
- The reaction is endergonic
A
- Energy is needed to start the reaction
- The reaction is endergonic
18
Q
They type of reaction in which organic polymers are formed from their subunits is called:
- hydrolysis
- condensation
- oxidation
- saturation
- deconstructionism
A
Condensation
19
Q
The compartmentalization of areas within eukaryotic cells:
- Allows for a smaller overall cell size relative to prokaryotic cells
- Allows them to perform several biochemical functions simultaneously
- Decreases their overall biochemical efficiency compared to prokaryotic cells
- Makes them more susceptible to sudden environmental changes
- Is more complex in animal cells than in plant cells
A
- Allows them to perform several biochemical functions simultaneously
20
Q
Which membrane component is most important for allowing large, charged molecules to pass through the membrane?
- Peripheral proteins
- Cholesterol
- Glycosylated lipids
- Transmembrane proteins
- Carbohydrate channels
A
- transmembrane proteins
21
Q
The concentration of solutes outside a cell is lower than the concentration of solutes inside the cell. Compared to its surroundings, the cell is:
- hypertonic
- hypotonic
- isotonic
A
Hypertonic
22
Q
The process that involves the selective uptake of a specific cargo molecule into the cell through receptor binding is:
- pinocytosis
- receptor-mediated endocytosis
- autophagocytosis
- phagocytosis
- receptor-mediated exocytosis
A
Receptor-mediated endocytosis
23
Q
If a lysosome bursts inside a cell, the immediate result is likely to be:
- the cell will be unable to build proteins
- the cell will be digested from within
- it will be repaired with no loss of function
- the cell will divide into daughter cells
- DNA will be transposed to the nucleus
A
The cell will be digested from within
24
Q
Catabolism is:
- the ATP-dependent synthesis of biomolecules
- the process by which metabolic reaction are catalyzed
- the method that cells use to communicate
- the process of breaking down food molecules to synthesize ATP
- what happens if you have too many cells
A
- the process of breaking down food molecules to synthesize ATP
25
Enzymes fall into which category of biological macromolecules?
- nucleic acids
- carbs
- protein
- lipid
- none of these
protein
26
Which statement is NOT true with regard to plant cells?
- Plant cells possess cell walls
- Many plants lack centrioles
- Plant cells possess plasma membranes
- Plant cell slack mitochondria
- Plant cells possess lysosomes
- plant cells lack mitochondria
27
Competitive inhibitors are molecules that can bind an enzyme's _____ site, blocking the substrate from binding.
- tertiary
- active
- allosteric
- cofactor
- none of these
active site
28
A patient exhibits a diverse range of symptoms. Lab tests reveal that multiple metabolic processes are occurring at sub-normal levels due to the lack of nutrients and molecular building blocks. Tests reveal that cells are not secreting materials normally and have an improper ion balances. What cell organelle is not functioning properly?
- mitochondria
- peroxisomes
- lysosomes
- plasma membrane
- centrosomes
PLASMA MEMBRANE
29
The major structural elements of the cytoskeleton are:
- the extracellular matrix and the cell wall
- microtubules, microfilaments, and intermediate filaments
- the cytoplasm and cytosol
- cleavage furrows and g-actin
- proteoglycans and cellulose microfibrils
- microtubules, microfilaments, and intermediate filaments
30
What is the rough ER?
Site of protein sorting and secretion
31
What is the cytoskeleton?
Provides cell shape, organization, and movement
32
What is the nucleus?
Where most genetic material is organized/expressed
33
What is the cytosol?
Located outside of the membrane bound organelles, inside the plasma membrane
34
What is the golgi apparatus?
Site of modification, sorting and secretion of lipids and proteins
35
What are peroxisomes?
Site of hydrogen peroxide breakdown
36
What are ribosomes?
Site of polypeptide synthesis
37
What is the smooth ER?
Site of detoxification and lipid synthesis
38
What is the chloroplast?
Site of photosynthesis
39
What is the mitochondria?
Site of ATP synthesis
40
T/F: Bacterial chromosomes are circular and eukaryotic chromosomes are linear
True
41
T/F: Rosalind Franklin's X-Ray diffraction data was used by Watson and Crick to show that DNA is double stranded, helical molecule
True
42
T/F: Cancer cells have extremely high levels of telomerase enzyme activity.
True
43
T/F: In the genetic code, each amino acid is specified by only one codon.
False
44
T/F: DNA replication is semi-conservative
True
45
T/F: Prokaryotic cells have multiple origins of replication.
False
46
T/F: In both eukaryotes and prokaryotes, the replication fork for DNA replication proceeds in two directions, enabling replication fo both strands of DNA.
True
47
T/F: Beadle and Tatum provided evidence that a single gene controlled the synthesis of a single enzyme when they published the "one gene, one polypeptide" hypothesis.
True
48
T/F: Genes that are expressed at all times and at relatively constant levels are known as inducible genes.
False
49
T/F: The core promoter of a eukaryotic structural gene contains a short sequence of DNA called a TATA box, which is positioned about 25 base pairs upstream from the transcriptional start site.
True
50
T/F: Eukaryotic genes are clustered in groups called operons.
False
51
T/F: The anticodon is a triplet of nucleotides present on tRNA.
True
52
T/F: The "wobble hypothesis" states that the genetic code is degenerate.
True
53
T/F: Addition of nucleotides to a growing DNA strand requires the presence of a 3' OH group.
True
54
T/F: DNA replication in eukaryotes results in loss of nucleotides at the end of the chromosome
True
55
T/F: Translation of proteins in prokaryotes occurs in the cytoplasm
True
56
T/F: Eukaryotic DNA contains segments of DNA, called introns, that do not code for proteins.
True
57
If the GC content of a DNA molecule is 60%, what are the percentages of the four bases (G, C, T, A)?
G = 30%, C = 30%, A = 20%, T = 20%
58
Which of the following represents the lowest level (least compact) of eukaryotic chromosome condensation?
- Radial loop domain
- 30 nm fibers
- Heterochromatin
- DNA wrapping to form nucleosomes
- DNA wrapping to form nucleosomes
59
On the ribosome, during the process of translation:
- The uncharged tRNA is found in the A site
- The growing polypeptide chain is found in the E site
- The anticodon of the mRNA molecule binds first to the large subunit.
- The charged tRNA enters in the A site
- The mRNA enters through the P site
The charged tRNA enters the A site
60
Okazaki fragments do which of the following?
- Assist in forming the replication fork
- Bind to the origin of replication
- Are formed during the synthesis of the lagging strand
- Reform the double-helix following replication
Are formed during the synthesis of the lagging strand
61
Which fo the following is NOT correct concerning telomeres?
- Telomeres are areas of the chromosome which contain many protein-coding genes
- Repeating region sin telomeres are important for the binding of the enzyme telomerase
- Telomeres must be lengthened after each round of replication
- Telomeres help preserves chromosomal integrity
Telomeres are areas of the chromosome which contain many protein-coding genes
62
Ribosomes consist of two protein subunits and ____.
- tRNA
- rRNA
- short DNA
- telomeres
rRNA
63
A mutation in which of the following region sis least likely to affect gene function?
- Promotor
- Coding region
- Splice junction
- Intergenic region
- Regulatory site
Intergenic region
64
All of the following are part of a nucleotide EXCEPT:
- pentose sugar
- nitrogenous base
- phosphate group
- fatty acid group
fatty acid group
65
What is the correct order that describes the central dogma of molecular biology?
DNA, RNA, protein
66
Griffith's work with smooth and rough strains of S. pneumonia bacteria showed that:
- RNA transcription is essential for mouse survival
- Nonvirulent bacteria can be transformed if exposed to heat-killed virulent bacteria
- One gene provides the code for one enzyme
Nonvirulent bacteria can be transformed if exposed to heat-killed virulent bacteria
67
A cell's ability to control their level of gene expression is called:
gene regulation
68
What type of regulatory transcription factor binds DNA and increases the transcription of a gene?
- a regulator exerting positive control
- an activator exerting positive control
an activator exerting positive control
69
Genes organized into an operon are beneficial to certain bacteria because the operon allows for _____.
- Differential regulation of individual genes that encode proteins with a common function
- Coordinated regulation of a group of genes that encode proteins with a common function
- Separate regulation of individual genes that encode proteins with different functions
- Coordinated regulation of a group of genes that encode proteins with different functions
- Coordinated regulation of a group of proteins involved in numerous cellular activities
Coordinated regulation of a group of genes that encode proteins with a common function
70
Liver cells, mammary cells, and skin cells all contain the same genome; however, their respective proteomes vary drastically. This observation is best explained by what phenomenon?
- gene regulation
- cell division
- cell cycle control
- crossing over
- evolution
gene regulation
71
An example of gene regulation in eukaryotes is the differential expression of human globin genes such that:
all the above
72
T/F: Bacteria regulate gene expression in response to changes in their environment.
TRUE
73
A ____ operon is one whose transcription is kept at low levels by effector molecules.
- repressible
- inducible
- coinducible
- compressible
inducible
74
T/F: An organelle that is semi-autonomous can grow and divide independently
False
75
T/F: H+ electrochemical gradients are important in the production of ATP through aerobic respiration
True
76
T/F: NADPH is the electron carrier used in both photosynthesis and mitochondrial electron transport chain
False
77
T/F: During signal transduction, the original signal is converted to a new signal inside the cell.
True
78
T/F: Glycolysis is the primary energy-yielding pathway for anaerobic organisms, but is not widely used by aerobic organisms.
False
79
T/F: Proteoglycans consist of a protein core with covalently attached carbohydrates that form a hydrated gel-like network within extracellular matrix of tissues
True
80
T/F: Cyanide poisoning causes cell death due to a shut down of glycolysis.
False
81
T/F: G-protein coupled receptors are large proteins with seven membrane-spanning domains
True
82
T/F: Tight junctions are present between epithelial cells within an animal's digestive tract
True
83
T/F: Apoptosis is programmed cell death
True
84
T/F: Photosynthesis can only occur when oxygen is present
False
85
When placing red blood cells in fresh water,
- the red blood cell is hypotonic to fresh water
- the red blood cell is hypertonic to fresh water
- The red blood cell is isotonic to fresh water
- water moves from the red blood cell into fresh water
- the red blood cell is HYPERTONIC to the fresh water
86
The type of reaction in which organic polymers are formed from their subunits is called:
- hydrolysis
- condensation
- oxidation
- saturation
condensation
87
When a cell secretes a signaling molecule that binds to receptors on neighboring cells as well as the same cell, this is called ____.
- direct intercellular
- contact-dependent
- autocrine
- paracrine
- endocrine
Paracrine
88
Small molecules, such as cAMP, that relay signals within the cell are called:
- First messengers
- ligands
- g proteins
- second messengers
second messengers
89
Which of the following structures allow for the exchange of metabolites between the cytoplasms of two adjacent cells?
- adhesive junctions
- tight junctions
- gap junctions
- plasmodesmata
- last two
gap junctions and plasmodesmata (last two)
90
Which of the following characteristics best describes collagen?
- triple helix
- part of the extracellular matrix
- coated with carbohydrates
- most abundant protein in the ECM
- all the above
- triple helix
- part of the extracellular matrix
- most abundant protein in the ECM
91
Which of the following statements best describes the role of NAD+/NADH in glycolysis?
- NADH produces energy by directly creating the phosphoanhydride bonds in ATP
- NAD+ is used to carry electrons
- NADH is capable of pumping ions during glycoysis
- NADH is used primarily in substrate-level phosphorylation
- NAD+ is used to carry electrons
92
T/F: The victims of Tylenol cyanide poisoning could have been saved if medical personnel had administered oxygen therapy.
FALSE
93
During strenuous exercise, you may notice that your muscles burn. Why?
- Proteins are being digested to provide energy
- Carbon dioxide is building up in muscle and changing the pH
- Without oxygen, pyruvate is being converted to lactic acid
- ADP is accumulating, which produces a burning sensation
- Without oxygen, pyruvate is being converted to lactic acid
94
The most abundant polysaccharides in vertebrae extracellular matrix are called:
- glycosaminoglycans (GAGs)
- Hemidesmosomes (HDSs)
- Cellulogycans (CEGs)
- Plasmodesmata (PDSs)
Glycosaminoglycans (GAGs)
95
The light harvesting reactions of photosynthesis take place in the _____ membranes of chloroplasts.
- thyamine
- thiloplast
- thoroplast
- thylakoid
thylakoid
96
Which of the following substances is required in the citric acid cycle reactions as an electron acceptor?
- oxygen
- ADP
- coenzyme A
- NAD+
- CO2
NAD+
97
In eukaryotic cells, respiration occurs in the:
- Chloroplasts
- golgi bodies
- mitochondria
- ribosomes
- lysosomes
mitochondria
98
As a polypeptide is made, a ____ bond is formed between the carboxyl group in the last amino acid of polypeptide chain and the amino group in the amino group in the amino acid being added.
- covalent
- hydrogen
- electrostatic
- ionic
- phosphodiester
Covalent
99
Electrons are passed to the electron transport chain from which of the following substances?
- pyruvic acid
- NADH and FADH2
- oxygen and carbon dioxide
- ATP
- oxaloacetic acid
NADH and FADH2
