Dna - Code Or Life

Front 1

What are nucleic acids?

Back 1

They have the capacity to store the information that controls cellular activity

Front 2

What do nucleic acids do?

Back 2

They control:

- the specialization of celle to form tissues

- arrangement of tissues into organs

Front 3

What are the basic processes of life

Back 3

-movement

- nutrition

- respiration

- excretion

- growth

- reproduction

- responding to stimuli

Front 4

What do nucleic acids do to enable organisms to carry out the basic processes of life ?

Back 4

They control the synthesis of proteins

Front 5

What also act like proteins

Back 5

Enzymes

Front 6

What do enzymes do?

Back 6

They control the chemical processes

Front 7

What are the 2 nucleic acids found in cells

Back 7

- Deoxyribonucleic acid ( DNA )

- Ribonucleic acid ( RNA )

Front 8

Where is DNA found

Back 8

Mainly found in the nucleus of a cell where it forms an important part of the chromosomes that make up the chromatin network

Front 9

What is chromatin?

Back 9

Chromosomal material made up of DNA, RNA and histone proteins as found in a non - dividing cell

Front 10

What is extracellular DNA?

Back 10

Small amounts of DNA found outside the nucleus in mitochondria in plants and animals and in chloroplasts in plants

Front 11

Why were they called chromosomes and what does that mean

Back 11

They absorb dye very easily which is why they were called chromosomes as this makes them visible under a microscope but they can only be seen as individual threads when a cell is dividing

Front 12

Chromosomes ?

Back 12

Are long, thin, intertwined thread like structures made up of a strand of DNA wound around proteins

Front 13

What is the wound around proteins called

Back 13

Histones

Front 14

If histones are attached to DNA what does it do

Back 14

It helps it to coul up during cell division

Front 15

In a body ( somatic ) cells chromosomes occur like what?

Back 15

Homologous pairs

Front 16

What are genes

Back 16

Sections of DNA molecules that control hereditary characteristics

Front 17

Who discovered the structure of DNA

Back 17

Maurice wilkins and rosalind Franklin

Front 18

Who also became interested in DNA

Back 18

- Francis Crick

- James Watson

Front 19

What did James Watson discover ?

Back 19

Discovered spiral helical

Front 20

Who won the Nobel prize for DNA

Back 20

Watson, crick and wilkins

Front 21

What is the shape of DNA

Back 21

Is a long, twisted ladder, forming a stable, 3 dimensional double helix

Front 22

What are nucleotides

Back 22

The double stranded DNA molecules Is made up of releating units, building blocks linked to form long nucleic acids chains

Front 23

Each nucleotide is made up of

Back 23

- sugar molecules ( deoxyribose )

- phosphate molecule

- nitrogenous base

Front 24

What is the nitrogenous base made up of

Back 24

- adenine

- thymine

- guanine

- cytosine

Front 25

The four bases are what

Back 25

The foundation of the genetic code, instructing cells on how to synthesize enzymes and other proteins

Front 26

How is the double helix made up

Back 26

- the outer 2 strands of the ladder are formed by a chain of alternating sugar/ phosphate links.

- the rungs of the ladder are formed from pairs of bases linked by weak hydrogen bonds

- the nitrogenous base pairs are attached to the sugar molecules

Front 27

What does adenine bond with?

Back 27

Only bonds with thymine or uracil

A = T

A = U

Front 28

What does Cytosine bond with

Back 28

Bonds with guanine

C = G

Front 29

There are 2 groups of nitrogenous bases

Back 29

- purines

- pyrimidines

Front 30

What are purines

Back 30

They are made up of 2 rings of nitrogen, oxygen and hydrogen atoms.

Examples are guanine and adenine

Front 31

Pyridmidines are what

Back 31

Made up I'd one rings of similar atoms and are therefore much smaller that purines

Examples are thymine and cytosine and uracil

Front 32

What is it known as when determining the order of the bases in a DNA chain

Back 32

DNA sequencing

Front 33

What determines the genetic code

Back 33

The sequence of the four bases

Front 34

How do organisms differ

Back 34

The sequences in which the base pairs are strung together

Front 35

What is the role of DNA molecules

Back 35

- carry coded genetic information in each cell in the form of Gene's which provide a blueprint for an organisms growth and development by coding for a specific protein

- can replicate

Front 36

What are exons

Back 36

Protein coding regions of a DNA molecule

Front 37

What are they interrupted by

Back 37

Non coding regions called introns

Front 38

Non coding regions are known to form

Back 38

Functional RNA molecules

Front 39

Replication

Back 39

Is the process of making a new DNA molecule from an existing DNA molecule which is identical to the original molecule

Front 40

What phase does replication take place

Back 40

Interphase

Front 41

Why is replication necessary

Back 41

The dna needs to produce another molecule exactly the same as itself to ensure that the genetic code is passed on to each daughter cell formed during cell division.

Front 42

How does replication take place ?

Back 42

- the hydrogen bonds between the 2 strands break, allowing the strands to part

- free nucleotides in the cytoplasm bond to their matching , exposed base partners

- the 2 daughter DNA molecules each twist to form a double helix which then winds itself around the histones (proteins) forming a chromosome

Front 43

What is the structure or RNA

Back 43

- consists of a single strand

- the strand is much shorter

- the sugar is ribose

- it has 3 bases in common with DNA: adenine, cytosine, guanins but a base uracil replaces thymine

Front 44

What is the function of RNA

Back 44

RNA carries instructions from DNA in the nucleus to the ribosomes in the cytoplasm of a cell where it controls the synthesis of proteins from amino acids

Front 45

What are cell chemical processes controlled by

Back 45

Enzymes

Front 46

What are the different types of rna

Back 46

- messenger rna ( mRNA )

- transfer rna ( tRNA )

- ribosomal rna ( rRNA)

Front 47

What is transcription

Back 47

When mRNA is formed in the nucleus in the same way as DNAS replication takes places.

Front 48

Transcription is the process whereby

Back 48

DNA makes and codes mRNA

Front 49

How does transcription take place

Back 49

- the process starts when a small piece of DNA, a gene, unwinds and the two strands separate

- new nucleotides pair up with their complementary bases on one of the dna strands. This strand is called the template as it Carrie's the code

- the nucleotides join up to form a strand of mRNA. Therefore the dna transcribes its genetic code to the mRna

- note that a uracil base will pair with an adenine base

- a coveted strand of mrna breaks away from the dna. The dna then re-zips

- the relatively small mrna moves through the pores of the nuclear membrane and Carrie's the genetic code to the ribosomes which are the sites of protein synthesis

Front 50

What is an amino acids

Back 50

It is a long chain ( polymer) of small units

Front 51

How many different amino acids are involved in protein synthesis

Back 51

20

Front 52

What determines what type of protein is made

Back 52

The order in which amino acids are linked

Front 53

The sequence of amino acids is determined by

Back 53

Instructions from the genetic code

Front 54

How is the genetic code carried

Back 54

Carried as a sequence of code words which are transcribed to the mRna

Front 55

What is a codon

Back 55

When a codeword is made up of any three bases

Front 56

How many codons are there

Back 56

64

Front 57

The three codons that did not code for an amino acid are called what

Back 57

Stop codons

Front 58

What does the order of codons determine

Back 58

The sequence of amino acids which will determine which protein is made

Front 59

What happens at the ribosome

Back 59

The mrna Hinds to the ribosome at the start codon. The codons of the mrna act as a template that determines the order in which the amino acids are linked

Front 60

Each trna has 3 bases at one end called

Back 60

An anti codon

Front 61

What do anti codons do

Back 61

Pick up specific amino acids found in the cytoplasm and transfers it to a ribosome

Front 62

Translation of rna into proteins process

Back 62

- the ani codon bases link up to their complementary bases of the codon. As the code on the mrna is translated into a sequence of amino acids

- the trna molecule is released to carry more of its specific amino acid to the ribosome

- catalyzed by enzymes, the amino acids link together with peptide bonds to form polypeptide chain

- the polypeptide chains link together to form the final functional protein

Front 63

What is translation

Back 63

The process by which a specific protein is formed from a chain of amino acids due to the sequence of codons in the mrna which in turn was coded by the DNA

Front 64

What is the role of rRNA

Back 64

The rrna moves from the codon to codon along the mrna reading the code. Therefore plays an important role in the controlling the process of protein synthesis

Front 65

Where is the genetic code stored

Back 65

It is stored along the length of a dna strand as a sequence of the 4 bases

Front 66

The nucleotides are arranged into how many groups

Back 66

3

Front 67

What does each codon do

Back 67

It codes for a particular amino acid