Brainscape's Knowledge GenomeTM

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


See full index

Biology 3/4 > U3AOS1 What is the role of Nucleic Acids and Proteins in Maintaining Life? > Flashcards

U3AOS1 What is the role of Nucleic Acids and Proteins in Maintaining Life? Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

protein definition

A

one of the four main groups of macromolecules made up of amino acid chains folded into a 3D shape. A polymer of amino acids composed of 2 or more amino acids joined together by a peptide bond.

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

biomacromolecule definition

A

a large organic molecule found in organisms

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

polypeptide definition

A

a long chain of amino acids (proteins can be made up of one of many polypeptides), joined by polypeptide bonds.

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

polymer definition

A

a large molecule composed of a chain of repeating similiar, smaller molecules called monomers

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

peptide definition

A

amino acids linked together

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

dipeptide definition

A

2 amino acids

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

tripeptide definition

A

3 amino acids

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

proteome definition

A

all the proteins that are expressed by a cell or organism at a given time. The proteome of each cell is different due to their specialized function.
–> proteomes are more diverse than a genome (there are more proteins in a proteome than their are genes in a genome)

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

proteomics definition

A

the study of the proteomes
–> detect diseases by observing protein levels
–> used to design drugs to deal with specific proteins that are causing a disease or disorder

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

recall the seven types of protein functions/types

A
  1. Structural
  2. Regulation
  3. Contractile
  4. Immunoglobulin
  5. Receptor
  6. Transport
  7. Signalling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

define structural protein

A

fibrous and stringy. Provides support for skin, bone, tendons, ligaments and cartlidge.

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

define regulation protein

A

catalyse reactions, regulate body activity.

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

define contractile protein

A

control muscle movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define immunoglobin protein

A

defense mechanism against pathogens that cause disease

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

define receptor protein

A

detect stimuli, label cells as targets for hormones, allows cells to be recognized as self or non-self

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

define transport protein

A

carry molecules around the body

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

define signaling protein

A

transmits messages

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

monomer definition

A

a molecule that is the smallest building block of a polymer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

define amino acid

A

an organic molecule that are the monomer of proteins and consists of a basic amino group (-NH₂), an acidic carboxyl group (-COOH), and a unique organic R group (or side chain). Amino acids are the building blocks of proteins ands polypeptides. They play important roles in metabolic pathways, gene expression, and cell signal transduction regulation. There are 20 different amino acids, and linking them together forms polypeptides.

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

explain the significance of the R group in amino acids

A

the R-group uniquely determines the identity of a particular amino-acid. Each R-group has its own chemical properties which affect how different proteins interact with each other.
e.g an amino acid with a hydrophobic R-group is more likely to form bonds with other hydrophobic R-group amino acids than it would with an amino acid containing a hydrophilic R-group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

carboxyl group definition

A

the functional group of an amino acid molecules that contains a hydroxyl group (OH) and an oxygen double-bonded to a carbon atom.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

amino group definition

A

the functional group of aminos acid molecules that is made up of one nitrogen and two hydrogens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

R-group definition

A

the variable portion if an amino-acid molecule. It can be one of twenty variations and determines the identity of the amino acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

define hydrophobic

A

having a tendency to repel and be insoluble in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

hydrophilic definition

A

having a tendency to be attracted to and dissolve in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

recall the structure of an amino acid

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

explain condensation polymerisation of amino acids

A

The joining of amino acids occurs at a cells ribosomes via a condensation reaction, resulting in the formation of peptide bonds between adjacent amino acids.
- As each amino acid is brought into place by a transfer DNA molecule
- a hydroxyl group is broken off the carboxyl of one amino acid, and forms a covalent bond with a hydrogen from the amino group of another, forming a water molecule.
- The amino acid residues are then joined together in a covalent bond called a peptide bond.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

condensation reaction definition

A

a reaction where two monomers join to form a larger molecule, producing water as a by-product.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

peptide bond defintion

A

the chemical bond linking two amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

recall the four levels of protein structure

A
  1. Primary structure
  2. Secondary structure
  3. Tertiary structure
  4. Quaternary structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

define the primary structure of a protein

A

the sequence (list or order) of amino acids in a protein/ polypeptide chain in which the protein is made

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

define the secondary structure of a protein

A

formed when a polypeptide chain folds and coils by forming hydrogen bonds between amino acids of its different sections. When this occurs, structures such as alpha helices and beta-pleated sheets are formed. Random coils are irregular portions of the secondary structure that join alpha-helices and beta-pleated sheets.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

alpha helix definition

A

an organised coiled secondary structure of proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

beta pleated sheets definition

A

an organised folded secondary structure of proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

explain the structure of the alpha helix of a protein

A
  • a right hand spiraling of the polypeptide, with the side-chains pointing outward
  • spiralling is visually caused by repulsion between equally charged side-chains
  • once created, the structure is held in a tight coil by hydrogen bonds that form between the hydrogen in the amino group, and the oxygen in the carboxyl group four amino acids earlier.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

define tertiary structure of a protein

A

refers to the overall functional 3D-shape of a protein. For a protein to be functional, it must have a minimum of a tertiary structure. Formed when the secondary structures further fold by forming interactions and disulphide bonds between amino acids and R-groups of its different sections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

explain the formation/ composition of the tertiary structure

A

hydrophobic amino acid side chains usually point to the interior of the protein, and hydrophillic side chains point out into the cytosol. These hydrophillic side chains help to suspend the protein in the watery environment of the cell - so they dont sink.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

disulphide bond definition

A

a strong covalent bond occurring between two sulphur atoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

define the quaternary structure of a protein

A

formed when two or more polypeptide chains with tertiary structures join together. These polypeptides are held together by hydrogen bonds and the mutual attraction between polar amino acid side chains.

40
Q

conjugated protein definition

A

proteins that certain non-amino acid groups (prosthetics) added to them. A protein with a carbohydrate added is called a glycoprotein. If its a lipid prosthetic, the protein is called lipoprotein.

41
Q

prosthetic group definition

A

a non-protein group bound to a protein

42
Q

explain the connection between a proteins primary, tertiary and quaternary structure

A

the folding of a protein into its functional tertiary or quaternary structure relies on its primary structure. If there are any changes to the original sequence of amino acids, a protein may no longer be able to fold correctly and thus function normally.

43
Q

define nucleic acids

A

a polymer of nucleotide monomers. The class of macromolecules that includes DNA and RNA. All nucleic acids are polymers made out of nucleotide monomers that store genetic information and help produce the proteins required for survival.

44
Q

recall the two types of nucleic acids

A
  1. Deoxyribonucleic acids
  2. Ribonucleic acid
45
Q

define deoxyribonucleic acid

A

a double-stranded nucleic acid chain madeup of nucleotides that is located in chromosomes in the nucleus of Eukaryotic cells. Carries the instructions for proteins which are required for cell and organism survival.

46
Q

ribonucleic acid definition

A

a single-stranded nucleic acid chain madeup of nucleotides (unparied chain of nucleotides).
Formed against a template strand of DNA thats primary role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins.
Essential in coding, decoding, regulation and expression of genes.

47
Q

nucleotide definition

A

the monomer subunit of nucleic acids. Madeup of a nitrogen-containing base, a five-carbon sugar molecule (ribose in RNA and deoxyribose in DNA), and a phosphate group.

48
Q

explain the composition of multiple bonded nucleotides

A

when many nucelotides bond together, they form a poly-nucleotide chain. The bonds joining nucleotides are phosphodiester bonds, that form via condensation reactions that exist between the sugar group of one nucleotide and the phosphate group of another. The linkage of sugars and phosphate groups is commonly referred to as the sugar-phosphate backbone of nucleic acids.

49
Q

explain supercoiling

A
  • double-helix combines with proteins (particularly histones) as it condenses to form chromosomes.
  • as the DNA winds, it forms nucleosomes that supercoil to eventually form a chromosome.
50
Q

define phosphodiester bond

A

a strong covalent bond linking a five-carbon sugar to a phosphate group

51
Q

define a sugar phosphate backbone

A

a strong covalently linked chain of five-carbon sugar molecules and phosphate groups in a nucleic acid

52
Q

chromosome definition

A

a structure made of protein and nucleic acids that carries genetic information

53
Q

gene definition

A

a section of DNA that carries the code to make a protein

54
Q

define pyrimidine

A

a single-ringed nitrogenous base including Cytosine, Thymine and Uracil.

55
Q

define purine

A

a double-ringed nitrogenous base including Adenine and Guanine

56
Q

recall the three types of RNA

A
  1. Messenger RNA (mRNA)
  2. Transfer RNA (tRNA)
  3. Ribosomal RNA (rRNA)
57
Q

define messenger RNA

A

RNA molecules created through the process of transcription that are shorter, complementary copies of the template strand of DNA. Enables the code from the DNA to leave the nucleus and be decoded - attaching to the ribosome so that translation can occur (translated into a protein).
–> bases are decoded three at a time (a codon)

58
Q

define transfer RNA

A

RNA that recognises specific codons on the MRNA strand and add the corresponding amino acids (from the cytoplasm) to the polypeptide chain during protein synthesis (in the ribosome)
–> folds up on itself to create an anticodon at one ends, and an amino acid joining position at the other.

59
Q

define ribosomal RNA

A

RNA that acts together with particular proteins, making up the structural component of ribosomes.

60
Q

define gene

A

a section of DNA that carries the code to make a protein

61
Q

define the genetic code

A

the set of rules by which information is encoded in genetic material via transcription and translation into function protein products.

62
Q

define triplet

A

the sequence of three nucleotides in DNA coding for one amino acid

63
Q

define codon

A

the sequence of three nucleotides in mRNA coding for one amino acid

64
Q

define start codon

A

the sequence of three nucleotides in mRNA that signals the start of translation

65
Q

define stop codon

A

the sequence of three nucleotides in mRNA that signals the end of translation

66
Q

recall the four criteria for the genetic code

A
  1. Universal
  2. Unambiguous
  3. Degenerate
  4. Non-overlapping
67
Q

define universal in terms of the genetic code

A

nearly all living organisms use the same codons to code for specific amino acids

68
Q

define unambigious in terms of the genetic code

A

each codon is only capable of coding for one specific amino acid. E.g the codon UAA only codes for the amino acid leucine

69
Q

define degenerate in terms of the genetic code

A

while each codon only codes for one amino acid, each amino acid may be coded for by multiple different codons. E.g both the codons UAA and UUG code for the amino acid leucine. This provides a fegree of redundancy, where changes to the original DNA sequence through mutations may not necessarily lead to the insertion of a different amino acid

70
Q

define non-overlapping in terms of the genetic code

A

each triplet or codon is read independently, without overlapping from adjacent triplets or codons.

71
Q

define the promotor region of a gene

A

an upstream binding site for RNA polymerase to DNA, which is an enzyme responsible for transcription. Denotes the starting position and direction of transcription.

72
Q

define introns on a gene

A

regions of non-coding DNA that do not contribute to the final protein as they are removed during RNA processing (post-transcriptional modifications). Only contained in eukaryotic genes.

73
Q

define exons on a gene

A

regions of coding-DNA, which are transcribed and translated into the final protein. Found in both eukaryotes and prokaryotes.

74
Q

define the termination sequence in a gene

A

a sequence of DNA that signals for the end of transcription and does not code for a protein.

75
Q

define the operator region in a gene sequence

A

serves as the binding site for repressor proteins; when the repressor protein is bound it will inhibit gene expression. Only in prokaryotic genes, as eukaryotes have different regions for regulating gene expression.

76
Q

define the leader region in a gene sequence

A

section of DNA upstream of the coding region, and downstream of the promotor and operator that regulates gene expression in prokaryotes.

77
Q

define RNA polymerase

A

the enzyme responsible for constructing a pre-mRNA sequence from a DNA sequence during transcription

78
Q

define repressor protein

A

a protein coded for by a regulatory gene that prevents gene expression by binding to its operator.

79
Q

define template strand

A

non-coding strand of DNA double helix transcribed by RNA polymerase to produce a complementary pre-mRNA strand. Ordered in a 3’ to 5’ direction (pre-mRNA strand made from it is made in a 5’ to 3’ end)

80
Q

define coding strand

A

the second strand of a DNA double helix that is not transcribed by RNA polymerase. Contains an identical sequence to the mRA produced - except thymine is replaced with uracil in mRNA - and runs in a 5’ to 3’ direction.

81
Q

define gene expression

A

the process pf reading the information stored within a gene to create a function product, typically a protein or non-coding strands of RNA.

82
Q

recall the three stages of gene expression involved in the production of proteins

A
  1. Transcription
  2. RNA processing
  3. Translation
83
Q

define transcription

A

the process whereby a sequence of DNA is used as a template to produce a complementary sequence of mRNA that is able to leave the nucleus. The RNA polymerase enzyme runs along the template strand in a 3’ to 5’ direction, unwinding and unzipping the DNA, and building a complementary strand of RNA in a 5’ to 3’ direction.

84
Q

recall the three steps involved in trancription

A
  1. Initiation
  2. Elongation
  3. Termination
85
Q

define initiation - TRANSCRIPTION

A

to initiate transcription, specific transcription factor proteins bind to the promoter region. This signals for the weak hydrogen bonds between the two strands of DNA to break, resulting in the bases of each strand being exposed and the DNA helix being unwound and unzipped. RNA polymerase is then able to start transcription.

86
Q

define elongation - TRANSCRIPTION

A

RNA polymerase moves along the template strand of DNA< reading the nucleotide sequence and uses-free-floating complementary RNA neucleotides to produce a new single-stranded RNA molecule known as pre-mRNA. The pre-mRNA molecule is synthesised in a 5’ to 3’ direction, so new RNA nucleotides are added to the exposed 3’ end. This pre-mRNA has a complementary nucleotide sequence to the DNA template strand.

87
Q

define termination - TRANSCRIPTION

A

transcription ends when RNA polymerase reaches the termination sequence of a gene, signalling the end of transcription. RNA polymerase then detaches, releasing the pre-mRNA molecule and the DNA molecule winds up again into a double helix. The pre-mRNA molecule is then processed to become mRNA, carrying the message for protein synthesis from DNA in the nucleus to the ribosomes located in the cytosol or connected to the rough endoplasmic reticulum of the cell.

88
Q

define RNA processing

A

refers to the series of modifications that a primary RNA transcript (also called a pre-mRNA in eukaryotes) undergoes to become a mature, functional RNA molecule. These processes are crucial for ensuring that the RNA is stable, correctly formatted, and functional for translation (in the case of mRNA) or other roles.

89
Q

recall the two alterations made to pre-mRNA in RNA processing

A
  • The addition of a methyl-guanine cap (methyl-G cap) at the 5’ end and a chain of adenine
    nucleotides (poly-A tail) to the 3’ end serve to stabilise the mRNA molecule, preventing it
    from degrading and allowing it to bind to ribosomes during translation.
  • the removal of introns and splicing of exons together via splicesomes.
90
Q

define splicesome

A

the enzyme that removes introns from the pre-mRNA molecule and joins exons together during RNA processing

91
Q

define alternative splicing

A

the process whereby different exons may be spliced together, resulting in a single gene producing multiple different mRNA strands

92
Q

anticodon defintion

A

the sequence of three nucleotides on a tRNA molecule that recognises a specific sequence of three nucleotides (codon) on a mRNA strand.

93
Q

define translation

A

the process whereby an mRNA sequence is read to produce a corresponding amino acid sequence to build a polypeptide in ribosomes in the cytosol of attached to the rough endoplasmic reticulum of the cell.

94
Q

recall the three steps involved in translation

A
  1. Initiation
  2. Elongation
  3. Termination
95
Q

define initiation - TRANSLATION

A

the 5’ end of the mRNA molecule binds to the ribosome and is read until the start codon is (AUG) is recognised. Then, a tRNA molecule with a complementary anticodon (UAC) binds to the ribosome and delivers the amino acid methionin, signifying the commencement of translation.

96
Q

define elongation - TRANSLATION

A

After the first amino acid is attached, the mRNA molecule is fed through the ribosome
so that the next codon can be matched to its complementary tRNA anticodon. Then,
complementary tRNA molecules deliver specific amino acids to the ribosome, which bind
to adjacent amino acids with a peptide bond via a condensation reaction. The first tRNA
molecule then leaves the ribosome and is free to pick up another amino acid, and the next
mRNA codon is exposed for more tRNA-delivered amino acids to add to the growing amino
acid chain.

97
Q

define termination - TRANSLATION

A

The reading of mRNA, delivery of amino acids by tRNA, and the linking of amino acids in
the polypeptide chain continues until the ribosome reaches a stop codon on the mRNA
molecule. The stop codon signals the end of translation as there are no corresponding
tRNA molecules. The polypeptide chain is then released by the ribosome into the cytosol or
endoplasmic reticulum.

Biology 3/4 (1 decks)

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