Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry > Option B: Biochemistry HL > Flashcards

Option B: Biochemistry HL Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

How many dissociation constants does a cationic form of 2-amino acids with non-ionizable side-chain have?

A

two: -COOH and -NH3^+
- COOH has relatively higher acidity and dissociates more easily than the protonated amino group, so pKa1 characterizes the equilibrium between the cation and the zwitterion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Acid-base buffer

A

Contains a weak conjugate acid-base pair which can neutralise small amounts of strong acids and bases without significantly changing the pH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Buffer pH range of an amino acids as acid-base buffer and why?

A

from pH = pKa1 - 1 to pKa1 + 1
and
from pH = pKa2 - 1 to pKa2 + 1

outside of these ranges, the amino acids exist predominately as a single ionic species and loses its ability to maintain a constant pH of the solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the role of protein buffers?

A

They maintain a constant pH of biological fluids, which is essential for the integrity of body tissues and enzyme functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Allosteric site

A

Many enzymes can temporarily bind to specific molecules via weak non-covalent interaction.
When allosteric site is occupied, the shape of the enzyme changes, which alters the configuration of the main active site, which affects the stability of the enzyme-substrate complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Non-competitive inhibition

A

When substrate and the inhibitor have different chemical structures and bind to different sites of the enzyme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Competitive inhibition

A

When substrate and the inhibitor have similar chemical structure and the inhibitor may occupy the main active site fo the enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Michaelis-Menten equation

A

v = (Vmax [S])/(Km + [S])

v: actual reaction rate
Vmax: maximum reaction rate
Km: Michaelis constant, which is equal to the substrate concentration when v=0.5Vmax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Turnover number

A

the maximum number

of substrate molecules that one molecule of enzyme can convert to product per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does small km (Michaelis constant) mean?

A

A small Km
indicates high affinity, which means that
enzyme–substrate complex ES is particularly stable and the rate will approach Vmax
even at relatively low substrate concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Protein assay

A

Analytical procedure that detects proteins and the determines their concentrations in solutions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

UV-vis spectroscopy

A

Technique that measures the absorption of UV and/or visible light by proteins or their complexes with organic dyes and transition metal ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why almost all proteins absorb UV light?

A
  • due to the presence of aromatic rings in phenylalanien, tyrosine and tryptophan residues
  • complexes of proteins with transition metal ions absorb visible light due to d-orbital electron transitions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Absorbance of a sample

A

The logarithmic ration between the intensity of light emitted by the monochromator (Io) and the intensity of light passed through the sample (I)

A = log (Io/I)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Beer-Lambert law

A

A = εcL

where L is the cuvette length and ε is a constant (known as the molar absorptivity or extinction coefficient) that depends on the solvent nature and the temperature of the solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Nucleic acids

A

Condensation polymers of nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Nucleotides

A

Products of condenstaion of a nitrogenous base, a pentose sugar (ribose or deoxyribose) and phosphoric acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Nitrogenous bases

A

Heterocyclic aromatic amines that contain several nitrogen atoms and act as proton acceptors in aqueous solutions

  • derived from two parent amines: pyrimidine and purine
  • crystalline substance with high melting points due to the presence of multiple polar groups
  • insoluble in water because their molecules are held togehter by strong hydrogen bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Pyrimidine

A

cytosine, thymine, uracil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Purine

A

adenine, guanine

21
Q

Diester bridge

A

When nucleotides combine with one another, the phosphate groups form a digester bridge between 3’ and 5’ carbon atoms of adjacent pentode residues

22
Q

At what end of the strand does the synthesis of nucleic acid begin?

A

5’

23
Q

What is the sequencing of human genome useful for?

A
  • treating various diseases
  • designing new forms of medication
  • understanding human ancestry, migration, evolution and adaptation to environmental changes
24
Q

What are the concerns of the man genome project?

A

1) possible discrimination of genetically disadvantaged people
2) gene modification
3) access to genetic information

25
Q

Initiator proteins

A

Group of enzymes that separate the two DNA strands and create short polynucleotide fragments (primers) paired with the separated strands by complementary nitrogenous
bases

26
Q

DNA polymerase

A

Group of enzymes that add more nucleotides to the primers using the existing DNA
strands as templates

27
Q

RNA polymerase

A

During transcription, it reads the DNA sequence and produces an RNA molecule complementary to an existing DNA
strand

28
Q

point mutation

A

Single mismatched nucleotide in the DNA sequence

29
Q

What causes point mutations?

A
  • can occur naturally
  • UV light
  • ionising radiation
  • free radicals
  • mutagens
30
Q

Diester bridge

A

When nucleotides combine with one another, the phosphate groups form a digester bridge between 3’ and 5’ carbon atoms of adjacent pentode residues

31
Q

At what end of the strand does the synthesis of nucleic acid begin?

A

5’

32
Q

What is the sequencing of human genome useful for?

A
  • treating various diseases
  • designing new forms of medication
  • understanding human ancestry, migration, evolution and adaptation to environmental changes
33
Q

What are the concerns of the man genome project?

A

1) possible discrimination of genetically disadvantaged people
2) gene modification
3) access to genetic information

34
Q

Initiator proteins

A

Group of enzymes that separate the two DNA strands and create short polynucleotide fragments (primers) paired with the separated strands by complementary nitrogenous
bases

35
Q

DNA polymerase

A

Group of enzymes that add more nucleotides to the primers using the existing DNA
strands as templates

36
Q

RNA polymerase

A

During transcription, it reads the DNA sequence and produces an RNA molecule complementary to an existing DNA
strand

37
Q

point mutation

A

Single mismatched nucleotide in the DNA sequence

38
Q

What causes point mutations?

A
  • can occur naturally
  • UV light
  • ionising radiation
  • free radicals
  • mutagens
39
Q

Biological pigments

A

Coloured compounds produced in living organisms

Have extensive systems of alternate single and double carbon-carbon bonds.

40
Q

What does the colour of the biological pigment depend on?

A

Molecular structure and on the number of delocalised electrons

41
Q

Antioxidants

A

Protects cells from UV light, peroxides and free radicals, including a highly reactive single oxygen produced by photosynthesis

42
Q

Porphyrins

A

Biological pigments that are complexes of metal ions with large cyclic ligands.

The organic backbone of porphyrins (porphin) contains four nitrogen atoms in a highly conjugated heterocycle

43
Q

Haemoglobin in venous blood

A

Has a slightly lower pH and higher CO2 concentration than arterial blood, protons and CO2 bind to side-chains of amino acids in haemoglobin and act as non-competitive inhibitors

44
Q

Cytochrome c oxidase

A

a large metalloprotein assembly containing four heme prosthetic groups and several ions of other metals includingcopper, magnesium, and zinc.

45
Q

Anthocyanins

A

Biological pigments that give bright colours of flowers, ripe fruits, berries and vegetables

Are water soluble and concentrate in the vacuoles of plant cells

46
Q

Stereoisomers

A

Molecules that have the same sequence of atoms and chemicalbonds but different arrangements of atoms in space

47
Q

Configurational isomers

A

Stereoisomers that cannot be

transformed into one another without breaking a chemical bond

48
Q

What are the two types of configurational isomers?

A

1) cis-/trans- isomers

2) optical isomers

49
Q

CORN rule

A
  • identifies enantiomers of 2-amino acids:

1) CO-R-N: COOH, R. and NH2
2) position the molecule so that the H atom at the C2 carbon faces away from you
3) CORN is spelled clockwise for D-enantiomer and anti-clockwise for an L-enantiomer

Chemistry (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions