Download DO NOW

Questions
• How many letters are in the genetic
library?
• How many letters make a genetic code
word?
• How many genetic words (codons) are in
the genetic dictionary?
• How many amino acids are there in total?
• What does a terminator sequence do?
• AIM: How is the genetic code stored in a
DNA molecule?
• DO NOW: 2- What is the difference
between DNA and RNA?
• HOMEWORK: Textbook read page 305.
Reading check page 305.
• AIM: how is the nucleus organized?
• DO NOW: What is DNA and how is it
different from RNA?
• Homework: textbook read pages
293,296-297. Do the Reading check
questions on pages 293 and 297
DO NOW ANSWER
• DNA: deoxyribose nucleic acid
– Found in the nucleus
– Holds the genetic code
• Instructions to control all cell activities
• RNA: Ribonucleic acid
– Carries the message from DNA out of the
nucleus to the necessary cell parts
Tuesday 2/7/12
• AIM: How does the structure of DNA
relate to its function?
• DO NOW: how many chromosomes do
your cells have?
• How many genes?
• How many nuclei?
• Homework: read pages 293,296,297,299.
reading check questions on page
293,296,297
DO NOW ANSWERS
•
•
•
•
Somatic cells have 46 chromosomes
Gametes have 23 chromosomes
Our cells contain thousands of genes
Each cell has only one nucleus
YouTube - Structure of DNA
DNA Structure - YouTube
Why do our gametes have only
half the number of genes as our
body cells?
DNA: deoxyribonucleic acid
• It is one of the polymers
or biomolecules
discussed in the past
• Polymer: big molecule
made of small repeating
units
• Monomer: single unit
that bonds with other
monomers to build a
polymer
• DNA is a chain of
Nucleotides
Nucleotide
• The building blocks of nucleic acids
• Thousands of nucleotides combine to build
a nucleic acid
• There are two types of nucleic acids
– DNA
– RNA
• There are slight differences in the
structure of the nucleotides that build DNA
and RNA
Nucleotide
• The GENERAL or
BASIC structure of
ALL nucleotides is the
same
– Phosphate group
– 5-carbon sugar
– Nitrogen containing
base
DNA nucleotide structure
• Double helix
• 5 carbon sugar
(pentose) is
deoxyribose
• Adenine
• Thymine
• Cytosine
• Guanine
Structure of DNA double helix
• Nucleotides combine to
form: a double helix
made up of:
– Sugar-phosphate
“backbone”
– Nitrogen bases bonded in
the middle
• The double helix consists
of 2 anti-parallel
complementary strands
• Nitrogen bases are held
together by weak
Hydrogen bonds
Structure of DNA is a double helix
What do genes do?
Units of heredity that are passed
down from generation to
generation
Where are genes located?
On the chromosome which is in
the nucleus
How is DNA related to genes
and chromosomes?
Wednesday 2/8/12
• AIM: How is the structure of DNA related to its
function?
• DO NOW: Why is the nucleolus important?
Where in your bodies is DNA stored?
• Homework: textbook Reread page 297.
Answer the following questions
1-What are the base pair rules?
2-Which two bases form two hydrogen bonds?
3-Which two bases form three hydrogen bonds?
Nucleolus
• Compacted DNA inside of the nucleus
• Synthesizes RNA
Thursday 2/9/12
• AIM:How do the nitrogen base pairs hold the
code for our physical traits?
• DO NOW: 1- Take out last nights homework
• 2- If you have a DNA template with the
sequence TACGGTACTGGC what is the
complementary DNA strand?
• 3- Explain what the sugar phosphate backbone
is.
• HOMEWORK: Textbook page 299 questions
1,3,4,6
Inside of the nucleus
• DNA: deoxyribose nucleic acid
– Carries genes on it
– Genes are coding regions that build proteins
– Proteins lead to physical characteristics
– NOT ALL DNA IS MADE UP OF GENES
• Both coding (genes) and non-coding parts
of DNA are wrapped around special
proteins and form a structure called
chromatin
YouTube - Structure of DNA
Why is DNA a double helix?
Two strands of nucleotides that
form a spiral when bonded
together
Structure of DNA is a double helix
Use the picture below and tell me how the
nitrogen bases are held together
Hydrogen bonds hold nitrogen
bases together
Friday 2/10/12
• AIM: how can we build a DNA molecule?
• DO NOW: What does it mean when we
say the double helix is antiparallel?
• Which part of the nucleotide is responsible
for the double helix being antiparallel?
• HOMEWORK: YOU MUST VISIT THE
WEBSITE SPECIFICALLY THE PAGE
THAT HAS DNA VIDEOS. View some of
the videos
The two strands of DNA are
antiparallel
Monday 2/13/12
• AIM: How is RNA similar to DNA?
• DO NOW: Draw a deoxyribose sugar and number
each carbon properly.
• Which number carbon is the phosphate group
connected to? The nitrogen base connected to?
• Homework: Textbook read pages 304 to the top of
305 stop reading at RNA: A major player. Answer
the following questions:
1- What is gene expression?
2- How do your cells express genes?
3- List and describe the first and second stages of
gene expression
Structure of DNA double helix
• Nucleotides combine to
form: a double helix
made up of:
– Sugar-phosphate
“backbone”
– Nitrogen bases bonded in
the middle
• The double helix consists
of 2 anti-parallel
complementary strands
• Nitrogen bases are held
together by weak
Hydrogen bonds
• What is DNA built from?
• What are the 3 parts of a nucleotide?
• Where is the genetic code in a DNA
molecule? In the sequence of codons: 3
nitrogen bases in a row
BASE PAIR RULES
• Always Adenine
bonds to Thymine
with 2 H bonds
• Cytosine to Guanine
with 3 H bonds
• Why is the DNA double helix like a two
way street?
• Because the two strands of the double
helix run in opposite directions
• 5’-3’
• 3’-5’
• This is determined by the arrangement of
the deoxyribose carbons
• Build a DNA Molecule
What is the function of DNA?
Function of DNA is to carry the
genetic message from cell to cell
Genetic code
• Gene: specific sequence of DNA that
holds the code to build a protein
Tuesday 2/14/12
• AIM: how are RNA and DNA nucleotides
different?
• DO NOW: What is the 5 carbon sugar in
DNA? In RNA?
• Where is DNA located?
• What is the function of RNA?
• Homework: textbook page 305. List and
describe the 3 types of RNA. And do the
Reading check question on page 305
Gene: unique sequence of base
pairs that code for a protein
• DNA is compacted
into the nucleus of
the cell
DNA cannot get out of
the nucleus
It carries hereditary
information (genes)
RNA can leave the
nucleus
How can DNA get its information
out of the nucleus?
By making an RNA molecule
Nucleotide
Phosphoric acid=Phosphate group= PO4Structure of a nucleotide is how it is built
PO4- + pentose + nitrogen base
Function of a nucleotide is its job
1- To build nucleic acids
2- Makes up and carries the genetic code
a. DNA carries the code from cell to cell
b. RNA carries the code from inside the
nucleus to the ribosome
Tuesday 2/14/12
• AIM: how are RNA and DNA nucleotides
different?
• DO NOW: What is the 5 carbon sugar in
DNA? In RNA?
• Where is DNA located?
• What is the function of RNA?
• Homework: textbook page 305. List and
describe the 3 types of RNA. And do the
Reading check question on page 305
Structure of a Nucleotide in
RNA and DNA - YouTube
Nitrogen Bases
In total there are 5
nitrogen bases
–
–
–
–
–
Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)
Uracil (U)
Thymine builds ONLY
DNA nucleotides
Uracil builds ONLY
RNA nucleotides
DNA vs RNA nucleotide Pentose
DNA: 5- carbon sugar
is deoxyribose
RNA: 5-carbon sugar
is ribose
Deoxyribose has one less oxygen than ribose
DNA nucleotide structure
• Double helix
• 5 carbon sugar
(pentose) is
deoxyribose
• Adenine
• Thymine
• Cytosine
• Guanine
RNA Ribose Nucleic Acid
• 5- carbon sugar is
Ribose
• Nitrogen bases
• Adenine
• Uracil
• Cytosine
• Guanine
Base pair rules
•
•
•
•
DNA
A=T
T=A
C=G
Tuesday 2/16/12
• AIM: Where is the genetic code located?
• DO NOW: Compare DNA and RNA.
Make a table showing similarities and
differences
• HOMEWORK: textbook pages 313-315.
questions 1,2,3,5,6,7,8,11,12,15.
• YOU MAY SEE SOME OF THESE
QUESTIONS ON TOMORROW’S EXAM!
Where is RNA synthesized?
nucleolus
DNA(gene): TACTGCATAGTA
1- What is the complementary DNA strand?
2- How many codons are in this gene?
3- What is the primary transcript (RNA)
made from this gene?
• END EXAM 2/16/12
• List 5 physical characteristics you have in
common with your parents and or siblings.
• How did you get those similar
characteristics?
• Physical characteristics are inherited from
our parents
• HOW?
• Genes: carry the instructions for all
physical characteristics from cell to cell
• Where are genes located?
• HOW does the genetic code get out of the
nucleus to build the physical
characteristic?
• AIM: how are genes organized and carried on
the DNA double helix?
• DO NOW: 1- take out last nights homework.
• 2- Why do our cells need to get the genetic code
out of the nucleus?
• 3- How do our cells get the genetic code out of
the nucleus?
• Homework: Textbook Read page307. The
genetic code: three-Letter “words:
• 1-Question 1- What is a codon?
• 2-Page 310 Questions 1, 2 and 4
• AIM: How are genes organized and
carried on the DNA double helix?
• DO NOW: Explain how the structure of
DNA is different from the function of DNA.
• HOMEWORK: Textbook Read page 306
to the top of page 307. question 5 on page
310
• Aim: How is RNA synthesized from a
DNA template?
• DO NOW: complete the table
Structure of Nucleic Acids
Homework: Using the DNA gene sequence
TACGTACCAGCTACT
Create the complementary DNA strand and
the primary transcript (mRNA)
DNA: carries genes on it
• Codon: part of a gene sequence
• specific sequence of 3 nucleotides that
hold the code for an amino acid
• The nitrogen bases of a codon act as
genetic “words”
• When the words are translated,we get an
amino acid.
• EX: DNA (gene) TAC
• AIM:How Does transcription create an
mRNA molecule?
• DO NOW: 1- Take out last night’s
homework
• Where does transcription take place? Why
does RNA go to the ribosome? Where is
the ribosome?
• Homework: Textbook Read pages 308309. Reading check page 309
Transcription
• Makes a mRNA from a DNA template
• The purpose is to get the genetic code out
of the nucleus into the cytoplasm
• WHY?
• So that a protein can be build which then
leads to a physical trait
Gene: unique sequence of base
pairs that code for a protein
How is the eukaryotic Nucleus
organized?
• Chromosome: key feature to cell division!
– DNA double helix wrapped tightly around histone
proteins
•
•
•
•
Chromosomes are not DNA!!!!!!
DNA does help make up a chromosome
Total DNA in a single human is about 6 feet long
In order to fit into a cells nucleus, it is compacted
and intertwined with various proteins
• But most of the time DNa is in the form of
chromatin
Chromatin: DNA + protein
• But most of the time
DNA is in the form
of chromatin
Beads on a string
• Nucleosomes: The DNA
of chromatin is wrapped
around a complex of
histones
• Changes in folding
between chromatin and
the mitotic chromosomes
is controlled by the
packing of the
nucleosome complexes.
Chromatin vs chromosomes
• Chromtin is loosely packed DNA
– Form of DNA throughout most of the cell cycle
• Chromosomes are tightly bound chromatin
– Only formed during cell division
Organization of DNA
• Chromatin: loosely bound DNA- protein
complex that make up chromosomes
• Seen in non-dividing cells
• Chromosomes: long complex condensed
molecules of DNA wrapped around histones.
During mitosis chromosomes consist of two
sister chromatids
• Chromatid:one of two duplicated
chromosomes connected at the centromere.
They separate to form daughter chromosomes
at anaphase
Replicated DNA creates
chromatids
Sister chromatids and centromere
Human Chromsomes
• Human: 23 pairs for a total of 46
• Homologous chromosome: similar in size,
shape and pattern. (not identical chromosomes)
• Automsomes: chromosomes that are not sex
chromosomes. In humans there are 22 pairs
• Sex chromosomes: carry genes for sex
determination do not have homologous pairs
– Female XX
– Male XY
Homologous chromosomes
Homologous chromosomes