BELL RINGER

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BELL RINGER

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BELL RINGER 1. Name the process in which cells divide. 2. What must happen first before DNA replicates? 3. What are the base pairing rules? 4. The enzyme_____ is used ... – PowerPoint PPT presentation

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Title: BELL RINGER

1
BELL RINGER

1. Name the process in which cells divide.
2. What must happen first before DNA replicates?
3. What are the base pairing rules?
4. The enzyme________ is used for proofing
__________.
5. Using the diagram below can we identify the
backbone in this structure?
6. Name the structure indicated by the arrow
bracket below

2
R N A Protein Synthesis

Biology I

3
D N A

DNA contains genes, sequences of nucleotide bases
These Genes code for polypeptides (proteins)
Proteins are used to build cells and do much of
the work inside cells

4
DNA Begins the Process

DNA is found inside the nucleus
Proteins, however, are made in the cytosol of
cells by organelles called ribosomes
Ribosomes may be free in the cytosol or attached
to the surface of rough ER

5
Starting with DNA

DNA s code must be copied and taken to the
cytosol
In the cytosol, this code must be read so amino
acids can be assembled to make polypeptides
(proteins)
This process is called PROTEIN SYNTHESIS

6
Structure Function of RNA

RNA Ribonucleic acid
RNA like DNA consists of nitrogen bases,
sugar-phosphate polymers, but there are also some
differences.
There are 4 main differences b/t RNA DNA
The sugar in RNA is ribose, DNA has deoxyribose
RNA is single stranded, DNA is double stranded
RNA contains the base uracil, DNA has thymine
RNA is smaller in size compared to DNA

7
Comparison of Structures DNA RNA
8
Structure of RNA
9

?Since the base Thymine is being replaced by the
base Uracil lets answer the following
?For the following DNA sequence add the
complementary RNA nucleotides
T T A G G C T G G A T G C T A A C
? The complementary RNA sequence would be
A A U C C G A C C U A C G A U U G

10
Question

?What would be the complementary RNA strand for
the following DNA sequence?
DNA 5-GCGTATG-3

11
Answer

DNA 5-GCGTATG-3
RNA 3-CGCAUAC-5

12
? Another difference between DNA RNA is in the
function. DNA has only one function STORING
GENETIC INFORMATION in its bases. But there are
3 main types of ribonucleic acid each has a
specific job to do

Ribosomal RNA (rRNA) exists outside the nucleus
in the cytoplasm of cells in structures called
ribosomes. Ribosomes are small, granular
structures where protein synthesis takes place.
Messenger RNA (mRNA) records" information from
DNA in the cells nucleus and carry it to the
ribosomes. They serve as messengers to the cell.
Transfer RNA (tRNA) the function of transfer RNA
is to deliver amino acids one by one to protein
chains growing at ribosomes.

13
Examples of RNA
Transfer RNA
Messenger RNA
Ribosomal RNA
14
R-N-A TRANSCRIPTION

The following diagram is an example for gene
expression how the information in DNA is
translated into organisms traits
RNA molecules are copied by copying part of the
nucleotide sequence of DNA into a complementary
sequence in RNA
This process by which DNA is copied to RNA is
called Transcription, it requires the enzyme RNA
polymerase occurs in the nucleus of cells

15
Transcription occurs in 3 steps

Step 1 Transcription begins when RNA polymerase
binds to the promoter site (a specific sequence
of DNA that acts as a START signal)
Step 2 RNA polymerase unwinds separates
the two strands of DNA
Step 3 RNA polymerase adds links complementary
RNA nucleotides
? Transcription continues until RNA polymerase
reaches the STOP signal on DNA

16
Diagrams of RNA Transcription
17
mRNA Transcript

mRNA leaves the nucleus through its pores and
goes to the ribosomes

18
Animation of Transcription
19
THE GENETIC CODE

Proteins are made by the joining of amino acids
into long polypeptide chains, which contain any
combination of the 20 AA.
The language of mRNA is called the genetic code.
A sequence of 3 nucleotides in mRNA codes for
each AA, are called codons.
Codons consists of 3 bases that specify an AA,
therefore the genetic code is read 3 letters at a
time.

20
enetic Code
Genetic Code
21
Example of Using Genetic Code

?Below is an example of an RNA sequence
CGGUAAGAGUCG
? It would be read 3 bases at a time
CGG UAA GAG UCG
? Each codon is represented by a different AA
CGG UAA GAG UCG
Arginine Stop Glutamine Serine

22
Lets practice below

Using the following DNA sequence
ATCGTAACCGTTCTG
Transcribe the DNA sequence into an mRNA
sequence
UAGCAUUGGCAAGAC
Now break the mRNA sequence down where it can be
read
UAG CAU UGG CAA GAC
Now identify the Amino Acids
Stop Hist Tryp Glut Asp

23
The Genetic Code

?Use the code by reading from the center to the
outside ? Example AUG codes for Methionine
24
Name the Amino Acids

GGG?
UCA?
CAU?
GCA?
AAA?

25
GCode
26
Messenger RNA (mRNA)
27
Transcription
28
RNA Protein Synthesis

Proteins are made by joining amino acids into
long chains called polypeptides. The production
of these proteins is called protein synthesis.
Each polypeptide contains any of ____ Amino Acids
The language of mRNA instructions is called the
_____
Codons contain___ nucleotides that specify a
single AA
Some AA are represented by more than one codon
EX __ codons specify AA Leucine, what are they?
One codon AUG can represent Methionine or START
codon for protein synthesis.
? Stop codons are like periods at the end of
sentence!!

Name the codons for the following AA
Tyrosine
Alanine
Glutamine
Name the AA for the following codons
AAA
CUG
UAG

29
THE MAKING OF PROTEINS
Protein Synthesis Translation
30
R-N-A Translation Protein Synthesis

TRANSLATION
The decoding of an mRNA message into a
polypeptide chain (protein) is called
translation, which takes place on ribosomes
Amino Acids are transported by ribosomes tRNA
molecules, which have specific regions that bond
to AA
The loop attachment has a sequence of 3
nucleotides called anticodons.
The tRNA anticodon is complementary pairs with
the mRNA codons.
During translation or protein synthesis the cells
use info from mRNA to produce the proteins

31
? EX The tRNA anticodon UAC would bind with the
mRNA codon_______
A U G

mRNA is transcribed from the DNA in the nucleus
Translation begins when mRNA attaches to a
ribosome at the start codon
The pairing of codons anticodons causes AA to
attach to the growing polypeptide chain
Each AA is added to the chain until it reaches a
stop codon ? ending translation

THE PROCESS
32
Gene Expression
ReplicationTranscriptionTranslation in Action
33
Another Example of Translation
34
Protein synthesis

Protein Synthesis Pt. 2

35
Translation
36
Gene Expression Activity
37
(No Transcript)
38
M u t a t I o n s
39
MUTATIONS

What is a Mutation?
? A mutation is a permanent change in the DNA
sequence of a gene. Mutations in a gene's DNA
sequence can alter the amino acid sequence of the
protein encoded by the gene.
?There are two main types of mutations
Gene Chromosomal
Gene mutations results from changes in a single
gene there are two types
Point Frameshift Mutations

40
? Point mutations these affect one nucleotide,
because they occur at a single point in the DNA
sequence substitutes one nucleotide for
another. .

Example
DNA TAC GCA TGG AAT
mRNA AUG CGU ACC UUA
AA Met Arg Thr Leu
? Substitution
DNA TAC GTA TGG AAT
mRNA AUG CAU ACC UUA
AA Met Hist Thr Leu

41
? Frame shift mutations these include inserting
a extra nucleotide or deleting a nucleotide,
which shifts the reading frame of the genetic
message

DNA TAC GCA TGG AAT
mRNA AUG CGU ACC UUA
AA Met Arg Thr Leu
? Insertion
DNA TAT CGC ATG GAA T
mRNA AUA GCG UAC CUU A
AA Ile Ala Tyr Leu

42
Ex of Gene Mutations
43
Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin) Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin) Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin) Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin) Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin) Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin) Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin) Normal hemoglobin (eight out of the 146 amino acid units of normal hemoglobin)
Val His Leu Thr Pro Glu Glu Lys
Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin) Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin) Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin) Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin) Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin) Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin) Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin) Sickle-cell hemoglobin (the same section as above as found in Sickle-cell hemoglobin)
Val His Leu Thr Pro Val Glu Lys
Good red blood cells Good red blood cells Sickle cell blood cellspictures fromwww.cc.nih.gov/ccc/ ccnews/nov99/ Sickle cell blood cellspictures fromwww.cc.nih.gov/ccc/ ccnews/nov99/
The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US The function of normal human red blood cells, which are disk-shaped, is to transport oxygen from the lungs to the other organs of the body. Each red blood cell contains millions of molecules of hemoglobin that carries the oxygen.A slight change in the order of the amino acids in the hemoglobin molecule (valine substituted for glutamine), which has only 146 amino acids, causes sickle-cell disease. Abnormal hemoglobin molecules stick together and crystallize deforming the red blood cells. The deformed blood cells then clog tiny blood vessels impeding the flow of blood. Sickle-cell anemia kills about 100,000 people per year in the US
44
The molecular basis of sickle-cell disease
45
Chromosomal M U T A T I O N S

? Environmental factors including radiation,
chemicals, and viruses, can cause chromosomes to
break if the broken ends do not rejoin in the
same pattern, this causes a change in chromosomal
structure.

46
Types of Chromosomal Mutations

?Inversion a segment that has become separated
from the chromosome is reinserted at the same
place but in reverse the position and sequence
of genes are altered.
? Translocation a chromosomal segment is removed
from one chromosome and inserted on another
chromosome
? Deletion is a type of mutation in which an end
of a chromosome breaks off or when two
simultaneous breaks lead to the loss of a
segment. a. Even if only one member of pair
of chromosomes is affected, a deletion can cause
abnormalities. b. Cri du chat syndrome is
deletion in which an individual has a small head,
is mentally retarded, has facial abnormalities,
and abnormal glottis and larynx resulting in a
cry resembling that of a cat.
? Duplication is a doubling of a chromosomal
segment. a. A broken segment from one
chromosome can simply attach to its homologue.
b. Unequal crossing-over may occur.