Brainscape's Knowledge GenomeTM

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


See full index

Biology > Nucleic Acids > Flashcards

Nucleic Acids Flashcards

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

What is a monomer?

A

Molecule that when repeated makes up a polymer

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

What is a nucleotide?

A

Molecule consisting of a five-carbon sugar, a phosphate group and a nitrogenous base

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

What is a polynucleotide?

A

Large molecule containing many nucleotides

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

What are Nucleotides? (Detailed)

A

Phosphate esters of pentose sugar, where a nitrogenous base is linked to the c1 (carbon 1 atom) of the sugar residue, and a phosphate group linked to either the c5 or c3 of the sugar residue, by covalent bonds formed by condensation reaction

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

What is a double helix?

A

Shape of DNA molecule, due to coiling of the two sugar-phosphate backbone strands into a right-handed spiral configuration

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

What is the monomer of nucleic acids?

A

Nucleotides

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

What is the polymer formed by joining nucleotides?

A

Nucleic acids (DNA and RNA)

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

Name of RNA and DNAs pentose sugar?

A

RNA-ribose

DNA-deoxyribose

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

When do nucleotides become phosphorylated nucleotides?

A

What they contain more than one phosphate group. Example- ADP (adenosine diphosphate)

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

What is ATP?

A

A phosphorylated nucleotide. It is an energy-rich end-product of most energy releasing biochemical pathways, and is used to drive most energy requiring metabolic processes in cells

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

What can nucleotides help regulate?

A

Many metabolic pathways

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

What may nucleotides be components of?

A

Coenzymes

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

Difference between nucleotide and nucleoside?

A

Nucleotide- nitrogenous base, pentose sugar, phosphate group

Nucleoside- nitrogenous base, pentose sugar

Adenosine is a nucleoside

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

Where is DNA usually found?

A

Nuclei of all eukaryotic cells, within cytoplasm of prokaryotic cells and also inside some viruses

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

Structure of DNA

A

Polymer as it is made up of repeating monomeric units called nucleotides
Consists of 2 polynucleotide strands
Two strands run in opposite direction (antiparallel)
Each nucleotide consists of phosphate group, deoxyribose and one of 4 nitrogenous bases
Covalent bond between sugar residue and the phosphate group in nucleotide is also called phosphodiester bond
Long so they can carry a lot of encoded genetic information

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

What bases in DNA are purine and which are pyrimidine?

A

Purine - adenine or guanine (two rings)

Pyrimidine - thymine or cytosine (one ring)

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

How are the 2 antiparallel DNA strands joined?

A

Hydrogen bonding
A-T with 2 hydrogen bonds
G-C with 3 hydrogen bonds
Purine always pairs to pyrimidine, giving equal sized rungs on the DNA ladder
Can then twist into the double helix to give it stability

18
Q

What do hydrogen bonds allow?

A

Allow the molecule to unzip during transcription and replication

19
Q

Describe how DNA is antiparallel?

A

The two strands of DNA run in opposite directions. One strand starts with 5’ and ends in 3’ and the other starts with 3’ and ends in 5’

20
Q

Why does DNA need to be very stable?

A

So the coded information within the base sequence is protected

21
Q

How is DNA organised in Eukaryotic cells?

A

Majority of DNA content is in nucleus
DNA is wound around his tone proteins
Each chromosome is one DNA molecule
Also a loop of DNA in mitochondria and chloroplasts

22
Q

How is DNA organised in prokaryotic cells?

A

In a loop in the cytoplasm, not in a nucleus
Not wound around his tone proteins
Naked

23
Q

What is DNA polymerase?

A

Enzyme that catalyses the formation of DNA from activated deoxyribose nucleotides, using single stranded DNA as a template

24
Q

What is helicase?

A

Enzyme that catalyses the breaking of hydrogen bonds between the nitrogenous base pairs of bases in the DNA molecule

25
Q

What’s semi conservative replication?

A

How DNA replicates, resulting in two new molecules, each of which contains one old strand and one new strand. One old strand is conserved in each new molecule

26
Q

Why does a DNA need to be copied? And when is it replicated?

A

So each new daughter cell relieves a full set of instructions.
The replication takes place during interphase

27
Q

To make a new copy of itself, each DNA molecule…

A
  • unwinds-double helix is untwisted, catalysed by a gyrase enzyme
  • unzips-hydrogen bonds between the nucleotide bases are broken. Catalyses by DNA helicase and results in 2 single strands of DNA with exposed nucleotide bases
28
Q

What happens after unzipping?

A

Free phosphorylated nucleotides bond to complementary exposed bases.
DNA polymerase catalyses addition of new nucleotides in the 5’ to 3’ direction.
Leading strand is synthesised continuously whereas lagging strand is in fragments that are later joined by ligament enzymes
Hydrolysis of activated nucleotides supplies energy to make phosphodiester bonds between sugar residue and one nucleotide and the phosphate group of the next molecule

29
Q

How loops of DNA undergo semi conservative replication?

A

A bubble sprouts from the loop and this unwinds and unzips and then complementary nucleotides join to the exposed nucleotides. Eventually the whole loop is copied

30
Q

How could mutations occur in DNA replication?

A

The wrong nucleotide may be inserted

This could change the genetic code

31
Q

How are mutations limited?

A

Enzymes that proofread and edit out such incorrect nucleotides, reducing the rate that mutations are produced

32
Q

What do you call different versions of the same gene?

A

Alleles

33
Q

What’s a gene?

A

A length of DNA that codes for a polypeptide or a length of RNA that is involved in the regulation gene expression

34
Q

What’s a polypeptide?

A

A polymer made up of many amino acid units joined together by peptide bonds.

35
Q

What is a protein?

A

A large polypeptide of 100 or more amino acids

36
Q

What’s transcription?

A

The process of making messenger RNA from a DNA template

37
Q

What’s translation?

A

Formation of a protein, at ribosomes, by assembling amino acids into a particular sequence according to the coded instructions carried from DNA to ribosome by mRNA

38
Q

How is RNA different to DNA?

A 
The 5 carbon sugar is ribose
Uracil replaces thymine
Single stranded
Shorter 
3 forms of RNA (messenger RNA. Transfer RNA and ribosomal RNA)
39
Q

What decides a proteins 3D shape?

A

It’s primary polypeptide chain

40
Q

Why is the genetic code described as
Universal
Degenerate
Non-overlapping

A

1) in almost all living organisms and same triplet of DNA bases codes for the same amino acid
2) almost all amino acids have more than one base triplet
3) it is read starting from a fixed point in groups of 3 bases

41
Q

Describe transcription

A

Gene unwinds and unzips
Hydrogen bonds between complementary nucleotides bases break
Enzyme RNA polymerase catalyses the formation of temporary hydrogen bonds between RNA nucleotides and their complementary unpaired DNA bases. U replaces T
Length of RNA is complementary to template DNA strand therefore called the coding strand
mRNA passes out of nucleus, through nuclear envelope and attaches to ribosome

42
Q

Describe translation

A

tRNA molecules bring amino acids and find their place where the anticodon binds by temporary hydrogen bonds to complementary codon on mRNA molecule.
Ribosomes moves along length of mRNA. Reads each code. Two amino acids adjacent to each other form peptide bond between each other
ATP is needed for polypeptide synthesis
Amino acid sequence is ultimately determined by gene
After polypeptide assembled. mRNA breaks down and can be recycled
New polypeptide is folded correctly into its 3D shape to carry out its function. It’s aided by chaperone proteins

Biology (6 decks)

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