bio topic 2 Flashcards
1
Q
How does beta-D-glucose look like?
A
Formula: C6H12O6, is a hexagon, has pair of H and OH groups placed interchangeably
2
Q
What is an example of anabolism?
A
Formation of maltose from two glucose molecules
3
Q
When does replication of DNA occur?
A
In S phase of interphase
4
Q
What is phosphorus used for in plan cells?
A
Composition of nucleic acids
5
Q
What is involved during oxidation?
A
The loss of electrons
6
Q
What can be a characteristic of a steroid molecule being a lipid?
A
Its low proportion of oxygen to carbon
7
Q
Which characteristics of glucose prevent its diffusion through the phospholipid bilayer?
A
It is polar and therefore hydrophilic
8
Q
What are the most frequently occurring elements in a living organism?
A
Nitrogen, oxygen, hydrogen, and carbon
9
Q
Which process is an example of catabolism?
A
The hydrolysis of protein
10
Q
Which can be explained by solvent properties of water?
A
Sodium chloride transported as Na+ and Cl- in blood
11
Q
Where do hydrogen bonds form?
A
Between the slight positive charge of hydrogen and slight negative charge of oxygen in different water molecules
12
Q
What property of water makes it a suitable coolant?
A
It takes a lot of energy for water to evaporate
13
Q
What is the consequence of the specific heat capacity for liquid water, ice ad water vapour?
A
Less energy is needed to warm water vapour than liquid water
14
Q
Which statement about water is correct?
A. The atoms within a molecule of water are held together by hydrogen bonds.
B. Water has a low heat capacity allowing enzymatic reactions to happen at a wide range of temperatures.
C. Water molecules are polar, therefore fatty acids do not dissolve.
D. Ice has a higher density than liquid water, therefore some organisms can live under the ice.
A
C
15
Q
Blood is a water-based medium. Which property of water makes it a good transport medium?
A. High specific heat
B. Transparency
C. Versatility as a solvent
D. It has its greatest density at 4°C
A
C
16
Q
What is the body mass index (BMI) for a man whose height is 2 m and mass 80 kg?
A
20 (80:(2.00^2))
17
Q
Which organic molecule may contain sulphur?
A. Proteins
B. Carbohydrates
C. Phospholipids
D. Nucleic acids
A
A
18
Q
What is a monosaccharide - glucose or maltose?
A
Glucose, because maltose consists of two molecules of glucose connected through hydrolysis
19
Q
What distinguishes cellulose from glycogen and starch?
A
Cellulose has a structural role whereas starch and glycogen function in energy storage
20
Q
Which molecule is a polysaccharide?
A. Glucagon
B. Glucose
C. Glycerol
D. Glycogen
A
D
21
Q
Is fructose a pentagon shaped monosaccharide?
A
Yes
22
Q
Is galactose a hexagon shaped monosaccharide with groups of OH and H on its side?
A
Yes
23
Q
Is lactose a monosaccharide?
A
No, it is a disaccharide made of glucose and galactose through hydrolysis like maltose
24
Q
Is maltose a monosaccharide?
A
No, it is a disaccharide made of two glucose molecules connected through hydrolysis
25
Is sucrose a disaccharide made of fructose and glucose?
Yep
26
Which molecules always contain hydrogen, carbon, and oxygen?
Proteins, carbohydrates, and fat
27
Which carbohydrates are used to provide energy storage in plants and animals?
Starch in plants and glycogen in animals
28
Which statement describes glycogen?
A. It is a hormone involved in the control of blood glucose.
B. It is a component of the cell wall in plants.
C. It is a monosaccharide converted to pyruvate during cell respiration.
D. It is a polysaccharide found in animals.
D
29
Bacteriorhodopsin is a membrane protein in bacteria that acts as a protein pump. Its structure
consists of a single polypeptide strand.
What is the highest level of protein structure shown by bacteriorhodopsin?
A. Primary
B. Secondary
C. Tertiary
D. Quaternary
C
30
What are the levels of proteins?
1. Primary (amino acid residue)
2. Secondary (alpha helix)
3. Tertiary (polypeptide chain)
4. Quaternary (assembled subunits)
31
What is the proteome of an individual?
The proteins synthesized as an expression of an individual's genes
32
Which statement correctly describes genome and proteome?
A. Only the genome but not the proteome can be analysed using gel electrophoresis.
B. The genome and the proteome are the same in all tissues in an organism.
C. In cells of different tissues, the genome is the same while the proteome varies.
D. Only mutations in the proteome but not in the genome cause any variability.
C
33
What is a proteome?
The entire set of proteins expressed by an organism at a certain time
34
The number of protein-coding genes in the human genome is estimated to be about 20 000, which is much less than the size of the proteome. What is one reason for this?
mRNA can be spliced after transcription.
35
Which below statement is true for tertiary structure of enzymes?
A. Tertiary structure is the sequence of amino acids in an enzyme.
B. Some enzymes do not have a tertiary structure.
C. An example of tertiary structure in an enzyme is the alpha helix.
D. A change in the tertiary structure of an enzyme may result in a change in the structure of the active site.
D
36
What enzymes are used in the process of creation of human insulin with the help of bacterial DNA?
Restriction endonuclease (enzyme that recognizes a specific DNA sequence, called a restriction site, and cleave the DNA within or adjacent to that cite) and ligase (an enzyme that can catalyze the ligation (joining) of two molecules by forming a new chemical bond)
37
What is the function of helicase enzyme?
It untwists the double helix of DNA to separate the strands and allows replication to occur
38
What is the function of DNA polymerase?
Its function is to accurately and efficiently replicate the genome in order to ensure the maintenance of the genetic information and its faithful transmission through generations (replication of DNA)
39
What is the function of RNA polymerase?
Replication of a strand of DNA into a strand of RNA
40
What is anabolism?
The chemical reaction in which from simple molecules the complex ones are synthesized; it requires energy
41
What is catabolism?
The breakdown of complex molecules into simple ones that are either oxidized to give energy or used in other anabolic reactions
42
Cell metabolism involves anabolic and catabolic reactions. Which process directly involves anabolism?
A. Active transport of ions
B. Release of energy from glucose
C. Production of intracellular enzymes
D. Breakdown of worn-out cell organelles by lysosomes
C
43
It is possible to attach β-galactosidase to alginate beads for use in the production of lactose-free milk. What are enzymes that have been attached in this way called?
A. Inhibited
B. Immobilized
C. Catalysed
D. Activated
B
44
What is an allosteric inhibitor?
Inhibitors that modify the active site of an enzyme so that substrate binding is reduced or prevented
45
Which of the following statements is true about enzymes?
A. They are used up in the reactions they catalyse.
B. Allosteric inhibitors bind to the active site.
C. They lower the energy of activation for a reaction.
D. They supply the energy of activation for a reaction.
C
46
Why is leucyl-tRNA synthetase not used to join the amino acid valine to tRNA?
A. Phosphorylation of valine occurs at a later stage.
B. Valine does not need to be activated to attach to tRNA.
C. Leucyl-tRNA synthetase is substrate-specific.
D. Valine has a different anticodon from leucine.
C
47
Structure of nucleotide in DNA strand
(From the inside of the strand) Organic base -> sugar -> phosphate group
48
Where can an entire genome of an organism be found?
In the DNA present inside the nucleus and mitochondria of an animal cell
49
What is the reason for the use of dideoxyribonucleotides to terminate sequences in base sequencing?
A. Nucleotides cannot form 5′ to 3′ linkages with dideoxyribonucleotides.
B. Nucleotides cannot form base pairs with dideoxyribonucleotides.
C. Dideoxyribonucleotides cannot form hydrogen bonds with deoxyribose.
D. Dideoxyribonucleotides do not have all four nitrogenous bases.
A
50
What is common to RNA and DNA?
A. Thymine
B Nitrogenous bases
C. Histones
D. Deoxyribose
B
51
What bonds are in a DNA helix?
Hydrogen bonds and covalent bonds
52
DNA numbering
5' -- 3'
--------
3' -- 5'
53
Anticodons with amino acids go on the...
Opposite to itself codons
54
Promoters are non-coding regions in DNA. What is the role of a promoter?
A. It starts translation.
B. It starts mRNA splicing.
C. It is a binding site for DNA polymerase during DNA replication.
D. It is a binding site for RNA polymerase during transcription.
D
55
What is a universal characteristic of the genetic code?
A. There are more than 64 different anticodons.
B. There are more nucleotides than codons.
C. There are more codons than amino acids.
D. There are two or more amino acids for each codon.
C
56
What applies to DNA base sequencing?
Promoters are transcribed along with the gene
57
What is the function of DNA primase?
Adds a short RNA primer to the template strand
58
What is the function of DNA polymerase I?
Replaces RNA primers with DNA
59
Which are two proteins that assist in the unwinding and separation of DNA strands during replication?
A Helicase and DNA polymerase III
B DNA gyrase and DNA polymerase I
C Helicase and DNA primase
D Single-strand binding protein and DNA gyrase
D
60
What is the reason for Taq DNA polymerase being used in the polymerase chain reaction (PCR)?
A It does not denature at high temperatures.
B It produces Okazaki fragments more rapidly.
C It allows translation to proceed rapidly.
D It works efficiently with helicase in PCR.
A
61
What occurs during DNA replication?
DNA molecules containing nucleotides from the original molecule are produced.
62
On which molecule is a codon found?
mRNA
63
The order of protein synthesis
1. Amino acid binds to tRNA
2. The tRNA moves from a binding site to another binding site on the ribosome
3. A ribosome reaches a stop codon
64
What DNA replication is like?
It is semi-conservative and also occurs during interphase
65
What is required to replicate DNA?
Free nucleotides carrying A, T, C, and G bases
66
Which two things are involved in both replication and transcription?
DNA and RNA
67
A strand of mRNA consists of the following nucleotides:
AUUCUGGCUA
Which of the following represents the non-transcribed (sense) strand of the DNA?
A. TAAGACCGAT
B. ATTCTGGCTA
C. UAAGACCAU
D. AUUCUGGCUA
B
68
What principle is necessary to prevent mutation of DNA during replication?
A. Base pairing is complementary.
B. One gene codes for one polypeptide.
C. Substrates are specific to enzymes.
D. The genetic code is universal.
A
69
What is NAD?
Nicotinamide adenine dinucleotide is a coenzyme central to metabolism, it is used to redox reactions as NAD+ or NADH
70
Energy that is released by oxidation reactions in the mitochondrial matrix is carried to the cristae of
the mitochondria. How is this energy carried?
A. As ATP
B. As glucose
C. In lysed water
D. As reduced NAD
D
71
What is a difference between aerobic respiration and anaerobic respiration in yeast?
A. Anaerobic respiration requires enzymes, aerobic respiration does not.
B. Anaerobic respiration requires glucose, aerobic respiration does not.
C. Anaerobic respiration produces ethanol, aerobic respiration does not.
D. Anaerobic respiration does not produce oxygen, aerobic respiration does.
C
72
Which gas produces most of the bubbles in bread dough?
A. Oxygen
B. Methane
C. Carbon dioxide
D. Water vapour
C
73
What happens during glycolysis for one molecule of glucose?
A. Two 3 carbon pyruvates are formed.
B. There is a net gain of two NADPH + H+.
C. There is a net loss of two ATP.
D. Two acetyl CoA are formed.
A
74
What happens in both respiration and photosynthesis?
A. Triose phosphates are decarboxylated.
B. NADPH is produced.
C. ATP is produced.
D. Electrons pass through ATP synthase.
C
75
What is formed from glucose during anaerobic cell respiration?
A. Lactate and ATP in cytoplasm
B. Carbon dioxide and water in mitochondria
C. Lactate and carbon dioxide in mitochondria
D. Carbon dioxide and water in cytoplasm
A
76
What happens to pyruvate during an anaerobic cell respitation?
Pyruvate turns to lactate
77
At what stage of meiosis do chromosome pairing and crossing over occur?
A. Interphase
B. Prophase 1
C. Metaphase 1
D. Prophase 2
B
78
What does an action spectrum for photosynthesis show?
A. The range of conditions over which photosynthesis can occur in a plant
B. The percentage of light absorbed at each wavelength by photosynthetic pigments
C. The percentage of light absorbed at each energy level by a plant
D. The relative amount of photosynthesis at each wavelength of light
D
79
Which wavelength of electromagnetic radiation is absorbed efficiently by chlorophyll for photosynthesis?
A. 45 nm
B. 45 µm
C. 450 nm
B. 450 µm
C
80
Some photosynthesis experiments require water that is free of carbon dioxide. What is the best way to produce this?
A. Boiling and cooling water
B. Adding hydrogencarbonate solution to water
C. Adding alkali to water
D. Immobilizing carbon dioxide on alginate beads
A
81
What do chloroplasts and mitochondria have in common?
A. Both are found in the cells of Filicinophyta.
B. Both contain grana.
C. Both occur in all eukaryotic cells.
D. Both are found in a Paramecium.
A
82
What does the Rf value in thin layer chromatography represent?
A. The distance travelled by the pigment front in a fixed time period
B. The distance from the origin to the solvent front at the end of the experiment
C. The ratio of distances travelled by the pigment and solvent fronts
D. The concentration of the pigment applied to the chromatography plate
C (Rf stands for retardation factor/relative front; Rf = distance travelled by the solute : distance travelled by the solvent)
