DNA: the code of life Flashcards by Maryam Mutalib

nucleic acid

a type of organic compound

DNA and RNA are examples of nucleic acids found in the nucleus

a macromolecule (made from monomers, building blocks called nucleotides) AKA polymer

How well did you know this?

Not at all

Perfectly

monomer

a building block

How well did you know this?

Not at all

Perfectly

nucleotide

the monomer of nucleic acid, which forms DNA and RNA

How well did you know this?

Not at all

Perfectly

DNA

 deoxyribonucleic acid is made up of nucleotides
 nitrogenous bases adenine, thymine, guanine and
cytosine ( g cat)
 carries the genetic code for protein synthesis
-type of nucleic acid

How well did you know this?

Not at all

Perfectly

nuclear DNA

DNA found in the nucleus

How well did you know this?

Not at all

Perfectly

extra- nuclear DNA

DNA found outside of the nucleus: mitochondrial and
chloroplastic DNA.

How well did you know this?

Not at all

Perfectly

double helix

the shape of DNA consists of two strands joined together
and twisted spirally

How well did you know this?

Not at all

Perfectly

hereditary

genetic information passed on from parent to offspring

How well did you know this?

Not at all

Perfectly

main functions of DNA (3)

1) Controls the functioning of cells
2) Regulate the functioning of genes
3) Passes on hereditary characteristics

How well did you know this?

Not at all

Perfectly

RNA

Type of nucleic acid

-RNA consists of nucleotides. Nitrogenous bases found in
RNA are adenine, uracil, guanine and cytosine

How well did you know this?

Not at all

Perfectly

messenger RNA (structure, formed location, function)

structure: single strand with unlimited number of nucleotides

formed location: in nucleoplasm, by complementary nucleotides on DNA template

function: carries genetic code from DNA in nucleus
- acts as messenger

How well did you know this?

Not at all

Perfectly

ribosomal RNA (structure, function)

structure: single strand (remember: its RNA so single stranded)

function: forms part of ribosome structure in cytoplasm
+ plays role in control of protein synthesis

How well did you know this?

Not at all

Perfectly

transfer RNA (structure, location, function)

structure: single strand folded back on itself like a hairpin (remember: its RNA so single stranded)

location: in cytoplasm

function: picks up amino acids in cytoplasm according to coding of according to coding of codon (of mRNA) and takes them to the ribosomes for protein synthesis

acts as transfer molecule

How well did you know this?

Not at all

Perfectly

what are the three types of RNA (ribonucleic acid)

1) messenger RNA (mRNA)
2) ribosomal RNA (rRNA)
3) transfer RNA (tRNA)

How well did you know this?

Not at all

Perfectly

where is RNA formed and by what

all formed in the nucleus by DNA.

How well did you know this?

Not at all

Perfectly

name where the 3 diff RNA can be found

1) Messenger RNA (mRNA) is formed in the nucleus but then enters the
cytoplasm where it attaches to ribosomes.

2) Ribosomal RNA (rRNA) is found in the ribosomes in the cytoplasm of the
cell.

3) Transfer RNA (tRNA) is found freely in the cytoplasm of the cell.

How well did you know this?

Not at all

Perfectly

what is the role of RNA

The three types of RNA are very important to the process of protein synthesis, with
each type playing a unique role.

How well did you know this?

Not at all

Perfectly

how are DNA and RNA similar (3)

they both:

1) contain sugar alternating with phosphate (pentose sugar)
2) contain the nitrogenous bases adenine, guanine and cytosine
3) play a role in protein synthesis

How well did you know this?

Not at all

Perfectly

how is DNA diff from RNA (4)

DNA:

1)contains deoxyribose sugar

2) double helix and coiled

3) contains the nitrogenous base thymine

4) found in the nucleus only

How well did you know this?

Not at all

Perfectly

how is RNA diff from DNA

RNA:

1) contains ribose sugar

2)single-stranded

3) contains the nitrogenous base uracil

4)found in the nucleus, ribosomes and
cytoplasm of cells

How well did you know this?

Not at all

Perfectly

describe the DNA replication process

The DNA double helix unwinds (due to enzymes running down the strand, enzyme name “gyrase”, donut shaped)
The weak hydrogen bonds between the
nitrogenous bases are broken. The DNA
strands separate (they unzip)(due to another family of enzymes called “helicase”, unzips by breaking the hydrogen bonds)
Each original DNA strand
serves as a template on which its
complement is built
Free floating nucleotides build a DNA strand onto
each of the original DNA strands, attaching
their complementary nitrogenous bases
(A to T and C to G)
This results in two identical DNA molecules. Each molecule consists of one
original strand and one new strand

How well did you know this?

Not at all

Perfectly

what is the importance of DNA replication

bef cell division (mitosis) , makes extra copy of each chromosome so that the 2 daughter cells produced have their own chromosomes

the gentic info present in the 2 daughter cells is the same as the mother cell

How well did you know this?

Not at all

Perfectly

genes

stretch of DNA, can be any lengths depending on how much info they have

each gene has the coding for one polypeptide

How well did you know this?

Not at all

Perfectly

non coding DNA

spaces betw genes

dont code for the making of polypeptide

regulates the expression of gene

How well did you know this?

Not at all

Perfectly

what are the complementary DNA nitrogenous base

guanine- cytosine adenine - thymine

what is the name of the pentose sugar in DNA

Deoxyribose (hint: from DNAs name )

why is DNA a polymer

it is made of Monomers called Nucleotides

central dogma of RNA and protein synthesis

DNA makes RNA and RNA makes proteins DNA-> RNA -> Protein recipe ->baker-> cake from recipe bk

what are the 2 stages in which protein synthesis occur

Stage 1: Transcription Stage 2: Translation

describe transcription stage in protein synthesis

1= A section of the DNA double helix unwinds. As a result, -the weak hydrogen bonds between the nitrogenous bases of DNA break - the DNA unzips (in this particular section of the DNA) NOTE: "polymerase" controls the transfer of code from DNA to RNA. 2= One strand acts as a template 3= This DNA template is used to form a complementary strand of messenger RNA (mRNA) - This is done using free RNA nucleotides in the nucleoplasm - The mRNA now contains the code for the protein which will be formed - Three adjacent nitrogenous bases on the mRNA are known as codons. These code for a particular amino acid. 4= mRNA moves out of the nucleus through a nuclear pore into the cytoplasm, where it attaches onto a ribosome

desc the translation stage in protein synthesis (5)

1- single mRNA strand formed in nucleus attaches to ribosome ( site for protein synthesis) 2- in ribosome: mRNA provide code for seq of amino acids (to form a specific protein (amino acid attached to tRNA) 3- tRNA picks up amino acid from amino acid pool in cytoplasm. each tRNA carries specific amino acid. (amino acid coded for by codons on mRNA, the tRNA anticodons also depend on codons on mRNA, anticodons are complementary to the codons) 4- amino acids join in sequence , this sequence det by mRNA codons. -> peptide bonds form betw 2 adjacent amino acids (this forms a dipeptide) -> more than 2 amino acids joined by peptide bonds (this forms a polypeptide chain) 5- after peptide bonds form . tRNA brks its bond with its amino acid (tRNA can now pick up another amino acid of same type - process continues till 50+ amino acids join = protein forms

mutation

A mutation is a change in the nitrogenous base sequence of a DNA molecule (or a gene)

amino acids

monomers of proteins

base triplet

three consecutive nitrogenous bases on DNA

transcription

1 st stage of protein synthesis – mRNA formed from DNA carrying code for the protein to be made

translation

2nd stage of protein synthesis – amino acids combine to form a protein

codon

three consecutive nitrogenous bases on mRNA – these are complementary to the triplet on DNA

anti-codon

three consecutive nitrogenous bases on tRNA – these are complementary to the codon on mRNA

name 7 DNA profiling / fingerprinting uses

1- identify crime suspects in forensic investigations (both samples, one from crime scene,looks exactly the same ) 2- identify dead bodies (from DNA bank government has) 3- identify relatives 4- as proof of paternity ( child DNA combo of mother + father ) 5- to determine probability and/ or causes of genetic defects 6- to trace missing people 7- to establish compatibility to tissue types for organ transplants

organic molecules that control the synthesis of proteins in all living cells by storing and transferring genetic info

nucleic acid (RNA)

DNA that occurs outside the nucleus

extranuclear DNA

long, thin thread - like structures that consists of DNA coiled around proteins called histones

chromosomes

a segment of a dna molecule that codes for a specific protein that controls a heritable characteristic and determines the appearance and functioning of an organism

gene

the three scientists that received the Nobel Prize for physiology/medicine in 1962 for the discovery of structure of DNA

1- James watson 2- Francis crick 3- Maurice wilkins

monomer of a nucleic acid composed of sugar, phosphate and a nitrogenous base

nucleotide

sugar molecule found in a nucleotide of dna

deoxyribose

the large nitrogenous base molecules, adenine and guanine

purine

the smaller nitrogenous bases, cytosine and thymine

pyrimidine bases

the code provided by the base sequence of DNA that gives the instructions for protein synthesis

genetic code

the dna that does not carry genetic info to produce proteins

non coding dna

the process by which dna duplicates to form 2 identical copies

replication

the 2 identical units of a chromosome after replication

chromatids

the structure that holds 2 chromatids together

centromere

the 1st step in the extraction of DNA where cells are broken down mechanically and/or chemically

lysis

the last step in the extraction of DNA during which the DNA becomes visible because it is insoluble in alcohol

precipitation / condensation

the barcode pattern formed by the base sequence of prepared processed DNA

dna profile / dna fingerprint

sugar molecule found in a nucleotide of RNA

ribose

the nitrogenous base that replaces thymine in rna

uracil

the type of RNA that caries the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm

mRNA

the type of RNA that picks up specific amino acids in the cytoplasm during protein synthesis and carries them to the ribosomes

tRNA

the type of RNA that forms part of the structure of the ribosomes in the cytoplasm and plays a role in the control of protein synthesis

rRNA

3 consecutive nitrogenous bases on a DNA strand that provides the code for a particular amino acid

base triplets

the process during which mRNA obtains the code for protein synthesis from DNA

transcription

the enzyme that controls the transfer of the code from the DNA to RNA and brks the weak hydrogen bonds betw the base pairs

RNA- polymerase

each grp of 3 consecutive bases on mRNA strand that codes for a particular amino acid

codon

3 exposed nitrogenous bases on a folded loop of each tRNA molecule

anticodon

the conversion of the code locked in the mRNA strand, to a particular amino acid sequence to build a specific protein

translation

dna profile/ fingerprint

descr of a persons genotype fro his/her unique DNA base pair seq, which is shown as a barcode pattern

forensic evidence

when biological specimans, eg, skin, blood, saliva, hair or semen are collected from a crime scene and the DNA is used as evidence In a court of law

forensic pathologist

the person who performs DNA tests on biological evidence found at crime scenes