basics bloque 1 Flashcards
(60 cards)
1
Q
- Which of the following are primary objectives of biochemistry?
(Select all that apply)
○ a) Understanding the chemical processes within living organisms.
○ b) Developing new physical laws.
○ c) Analyzing the structure-function relationship of biomolecules.
○ d) Creating economic models.
A
○ a) Understanding the chemical processes within living organisms.
○ c) Analyzing the structure-function relationship of biomolecules.
2
Q
- Biochemistry is considered an interdisciplinary science because it integrates:
○ a) Chemistry and Biology.
○ b) Engineering and Physics.
○ c) Astronomy and Psychology.
○ d) Geology and Sociology.
A
○ a) Chemistry and Biology.
○ b) Engineering and Physics.
3
Q
- Why is water essential in biological systems?
(Select all that apply)
○ a) It acts as a solvent for many biochemical reactions.
○ b) It forms weak hydrogen bonds that influence molecular interactions.
○ c) It has a high boiling point compared to other solvents.
○ d) It is highly non-reactive in biological systems.
A
○ a) It acts as a solvent for many biochemical reactions.
○ b) It forms weak hydrogen bonds that influence molecular interactions.
4
Q
- Hydrogen bonding in water leads to which of the following properties?
○ a) High surface tension.
○ b) Low specific heat capacity.
○ c) Solid water being less dense than liquid water.
○ d) Complete immiscibility with oils.
A
○ a) High surface tension.
○ c) Solid water being less dense than liquid water.
5
Q
- Biomolecules include which of the following categories?
(Select all that apply)
○ a) Carbohydrates.
○ b) Minerals.
○ c) Lipids.
○ d) Proteins.
A
○ a) Carbohydrates.
○ c) Lipids.
○ d) Proteins.
6
Q
- Interactions between biomolecules are stereospecific. Which of the following
are examples of stereospecific interactions?
○ a) Enzyme-substrate binding.
○ b) Non-specific ionic bonds.
○ c) DNA replication.
○ d) Random molecular collisions.
A
○ a) Enzyme-substrate binding.
○ c) DNA replication.
7
Q
- Buffers are important in biological systems because they:
○ a) Help maintain stable pH levels.
○ b) Prevent changes in temperature.
○ c) Neutralize strong acids and bases.
○ d) Are composed entirely of strong acids and bases.
A
○ a) Help maintain stable pH levels.
○ c) Neutralize strong acids and bases.
8
Q
- The Henderson-Hasselbalch equation can be used to:
○ a) Calculate the pH of a buffer solution.
○ b) Predict the outcome of a chemical reaction.
○ c) Measure the concentration of enzymes.
○ d) Determine the dissociation constant of a weak acid.
A
○ a) Calculate the pH of a buffer solution.
○ d) Determine the dissociation constant of a weak acid.
9
Q
- Future applications of biochemistry include which of the following?
(Select all that apply)
○ a) Designing new vaccines.
○ b) Developing space travel technologies.
○ c) Studying molecular evolution through phylogenetics.
○ d) Creating sustainable agricultural practices.
A
○ a) Designing new vaccines.
○ c) Studying molecular evolution through phylogenetics.
10
Q
- Which biochemical techniques are used for analyzing biomolecules?
(Select all that apply)
○ a) Chromatography.
○ b) Gene sequencing.
○ c) Ultrasound imaging.
○ d) Electrophoresis.
A
○ a) Chromatography.
○ b) Gene sequencing.
○ d) Electrophoresis
11
Q
- What is the main structural difference between starch and cellulose?
a. Starch has β(1→4) linkages; cellulose has α(1→4) linkages.
b. Starch has α(1→4) linkages; cellulose has β(1→4) linkages.
c. Starch is made of fructose; cellulose is made of glucose.
d. Both have the same structure.
A
b. Starch has α(1→4) linkages; cellulose has β(1→4) linkages.
12
Q
- Glycosaminoglycans are primarily found in:
a. Bacterial cell walls.
b. Plant cell walls.
c. Extracellular matrix of animals.
d. Cytoplasm of prokaryotes.
A
c. Extracellular matrix of animals.
13
Q
- Which of the following is a reducing sugar?
a. Sucrose
b. Maltose
c. Trehalose
d. Amylopectin
A
c. Trehalose
14
Q
- Which of the following polysaccharides is used for energy storage in animals?
a. Cellulose
b. Glycogen
c. Starch
d. Inulin
A
b. Glycogen
15
Q
- What type of bond connects monosaccharides in polysaccharides?
a. Phosphodiester bond
b. Glycosidic bond
c. Peptide bond
d. Hydrogen bond
A
b. Glycosidic bond
16
Q
- What is the difference between amylose and amylopectin?
a. Amylose is linear; amylopectin is branched.
b. Amylopectin is linear; amylose is branched.
c. Amylose is a disaccharide; amylopectin is a monosaccharide.
d. Amylopectin contains β(1→4) linkages; amylose contains α(1→4) linkages.
A
a. Amylose is linear; amylopectin is branched.
17
Q
- Which molecule contains β(1→4) glycosidic linkages?
a. Starch
b. Glycogen
c. Cellulose
d. Maltose
A
c. Cellulose
18
Q
- Which disaccharide consists of glucose and galactose?
a. Sucrose
b. Lactose
c. Maltose
d. Cellobiose
A
b. Lactose
19
Q
- What is a characteristic of reducing sugars?
a. They contain a free anomeric carbon.
b. They are unable to reduce Cu²⁺.
c. They form only α-glycosidic bonds.
d. They are always disaccharides.
A
a. They contain a free anomeric carbon.
20
Q
- Which lipid type is most abundant in biological membranes?
a. Triacylglycerols
b. Phospholipids
c. Steroids
d. Waxes
A
b. Phospholipids
21
Q
- Sphingolipids are characterized by:
a. Glycerol as their backbone.
b. The presence of sphingosine.
c. The ability to form triglycerides.
d. Exclusivity to plants.
A
b. The presence of sphingosine.
22
Q
- What is a key function of cholesterol in membranes?
a. Energy storage.
b. Pigment production.
c. Membrane fluidity regulation.
d. Hormone receptor activity.
A
c. Membrane fluidity regulation.
23
Q
- Which lipid is crucial for nerve impulse transmission?
a. Phosphatidylcholine
b. Sphingomyelin
c. Triacylglycerol
d. Cholesterol
A
b. Sphingomyelin
24
Q
- What is the function of eicosanoids derived from arachidonic acid?
a. Energy storage
b. Regulation of inflammatory responses
c. Membrane stability
d. Hormone receptor activation
A
b. Regulation of inflammatory responses
25
9. What type of linkage is found in waxes?
a. Phosphodiester linkage
b. Ester linkage
c. Glycosidic linkage
d. Amide linkage
b. Ester linkage
26
10. Which fatty acid is an omega-3 polyunsaturated fatty acid?
a. Oleic acid
b. Linolenic acid
c. Palmitic acid
d. Arachidonic acid
b. Linolenic acid
27
11. What is the primary role of phospholipids in the cell?
a. Energy storage
b. Hormone signaling
c. Structural component of membranes
d. Waterproofing
c. Structural component of membranes
28
7. What type of bond stabilizes the secondary structure of proteins?
a. Ionic bonds.
b. Hydrogen bonds.
c. Covalent bonds.
d. Disulfide bonds.
b. Hydrogen bonds.
29
8. The Ramachandran plot shows:
a. The sequence of amino acids in a protein.
b. Allowed dihedral angles of polypeptides.
c. Enzyme kinetics curves.
d. Folding pathways of proteins.
b. Allowed dihedral angles of polypeptides.
30
9. Which amino acid disrupts α-helices due to its rigid structure?
a. Glycine
b. Cysteine
c. Proline
d. Tyrosine
c. Proline
31
10. Which amino acid can act as a proton donor or acceptor near physiological pH?
a. Glutamine
b. Histidine
c. Tyrosine
d. Proline
b. Histidine
32
11. What type of bond stabilizes the tertiary structure of proteins?
a. Hydrogen bonds
b. Peptide bonds
c. Disulfide bonds
d. Glycosidic bonds
c. Disulfide bonds
33
12. What is the role of chaperones in protein folding?
a. Breaking peptide bonds
b. Preventing aggregation of unfolded proteins
c. Increasing mutation rates
d. Removing damaged proteins
b. Preventing aggregation of unfolded proteins
34
13. Which structural level of proteins involves the arrangement of multiple polypeptide
chains?
a. Primary structure
b. Secondary structure
c. Tertiary structure
d. Quaternary structure
d. Quaternary structure
35
14. Which amino acid is commonly found in turns due to its flexibility?
a. Glycine
b. Cysteine
c. Alanine
d. Lysine
a. Glycine
36
10. What is the quaternary structure of a protein?
a. The sequence of amino acids.
b. The folding of polypeptide chains.
c. The arrangement of multiple polypeptide subunits.
d. The types of bonds within the protein.
c. The arrangement of multiple polypeptide subunits.
37
11. Hemoglobin's oxygen-binding cooperativity is due to:
a. Alpha-helical structure.
b. Allosteric interactions between subunits.
c. Beta-pleated sheets.
d. Disulfide bond formation.
b. Allosteric interactions between subunits.
38
12. What helps proteins achieve their native conformation?
a. Chaperones
b. Denaturation agents
c. Peptidases
d. Lipid bilayers
a. Chaperones
39
13. What is the functional unit of a quaternary protein structure?
a. Subunit
b. Domain
c. Motif
d. Loop
a. Subunit
40
14. Oxygen binding cooperativity in hemoglobin is regulated by:
a. Disulfide bonds
b. Allosteric interactions
c. Hydrogen bonding with oxygen
d. Irreversible covalent modifications
b. Allosteric interactions
41
15. Which protein has a fibrous structure and provides tensile strength to connective
tissues?
a. Myoglobin
b. Collagen
c. Hemoglobin
d. Actin
b. Collagen
42
16. What property makes the α-helix a stable structure in proteins?
a. Hydrophobic side chains
b. Hydrogen bonding between NH and CO groups
c. Disulfide bonds between residues
d. Ionic bonds along the backbone
b. Hydrogen bonding between NH and CO groups
43
13. Which nucleotide drives protein synthesis?
a. ATP
b. GTP
c. CTP
d. UTP
b. GTP
44
14. Which of the following is a pyrimidine?
a. Adenine
b. Guanine
c. Cytosine
d. Hypoxanthine
c. Cytosine
45
15. Which bond gives nucleic acids their directionality?
a. Hydrogen bonds.
b. Glycosidic bonds.
c. Phosphodiester bonds.
d. Ionic bonds.
c. Phosphodiester bonds.
46
16. Which nucleotide is used in the elongation stage of translation?
a. ATP
b. GTP
c. CTP
d. UTP
b. GTP
47
17. Cyclic AMP functions as:
a. A structural component of membranes.
b. A second messenger in signal transduction.
c. A storage molecule for energy.
d. A DNA replication factor.
b. A second messenger in signal transduction.
48
18. What is the primary structural component of DNA?
a. Deoxyribonucleoside triphosphates
b. Ribosomes
c. Uracil
d. Sphingosine
a. Deoxyribonucleoside triphosphates
49
16. What is the primary enzyme involved in DNA replication?
a. RNA polymerase
b. DNA polymerase
c. Helicase
d. Primase
b. DNA polymerase
50
17. DNA replication is described as:
a. Conservative.
b. Dispersive.
c. Semiconservative.
d. Bidirectional.
c. Semiconservative.
51
18. Okazaki fragments are synthesized during:
a. Leading strand replication.
b. Lagging strand replication.
c. RNA transcription.
d. Protein synthesis.
b. Lagging strand replication.
52
19. What enzyme unwinds the DNA helix during replication?
a. Helicase
b. DNA ligase
c. Primase
d. Topoisomerase
a. Helicase
53
20. Which DNA polymerase is primarily responsible for proofreading in eukaryotes?
a. DNA polymerase α
b. DNA polymerase δ
c. DNA polymerase γ
d. DNA polymerase III
b. DNA polymerase δ
54
21. What process repairs mismatched base pairs during DNA replication?
a. Transcription
b. Proofreading
c. RNA editing
d. Splicing
b. Proofreading
55
19. Which RNA polymerase synthesizes mRNA in eukaryotes?
a. RNA polymerase I
b. RNA polymerase II
c. RNA polymerase III
d. Reverse transcriptase
b. RNA polymerase II
56
20. What is the function of the 5' cap in mRNA?
a. Splicing regulation.
b. Protection from ribonucleases.
c. DNA repair.
d. Protein cleavage.
b. Protection from ribonucleases.
57
21. Which RNA is responsible for bringing amino acids to ribosomes?
a. mRNA
b. rRNA
c. tRNA
d. snRNA
c. tRNA
58
22. Which RNA is processed by adding a 5' cap and a poly(A) tail?
a. tRNA
b. rRNA
c. mRNA
d. snRNA
c. mRNA
59
23. Which process removes introns from pre-mRNA?
a. Transcription
b. Translation
c. Splicing
d. Elongation
c. Splicing
60
24. What type of RNA catalyzes peptide bond formation in ribosomes?
a. rRNA
b. tRNA
c. mRNA
d. snRNA
a. rRNA
