Download Bell Work 2-23-16

Bell Work 2-23-16
DNA is a double helix in which two strands
are wound around each other. Each strand
is made up of a chain of nucleotides. The
two strands are held together by ________
bonds between adenine & _________ and
between guanine & ______________.
Held together by Hydrogen bonds
Adenine & Thymine Guanine & Cytosine
Bell Work 2-22-16
DNA is made up of nucleotides. Each nucleotide
has three parts:
1) A deoxyribose molecule (5 carbon sugar)
2) A phosphate group
3) A nitrogenous base
12-1 Key Concepts
• Avery and other scientists discovered that
the nucleic acid DNA stores and transmits
the genetic information from one
generation of an organism to the next.
• Watson and Crick’s model of DNA was a
double helix in which two strands were
wound around each other.
12-1 Vocabulary
• Transformation –
– the process in which one strain of bacteria is changed by a
gene or genes from another strain of bacteria.
• Bacteriophage– a virus that infects bacteria
• Nucleotides– a monomer of nucleic acids made up of a 5-carbon sugar, a
phosphate group, and a nitrogenous base.
• Base Pairing– the principle that bonds in DNA can form only between
adenine and thymine and between guanine and cytosine.
12-1
Adenine & Guanine are purines
Cytosine & Thymine are pyrimidines
12-2
What is the main difference between prokaryotic
cells & eukaryotic cells?
Prokaryotes (bactera) do NOT have a nucleus
Eukaryotes (plants/animals) DO have a nucleus
Prokaryotes store their DNA in the ___________
cytoplasm
Eukaryotes store their DNA in the _____________
nucleus
12-2
Eukaryotes chromosomes contain DNA and
protein, tightly packed together to form a
substance called chromatin.
Which stage of
Mitosis is this?
Interphase
12-2 Key Concept
During DNA replication, the DNA
molecule separates into two strands,
and then produces two new
complementary strands following the
rules of base pairing. Each strand of the
double helix of DNA serves as a
template, or model, for the new strand.
Complementary Strand
(Following DNA base pairing rules…)
CAG GCC TAC
GTC CGG ATG
A- T & C-G
12-2 Vocabulary
• Chromatin
– granular material visible within the nucleus; consists
of DNA tightly coiled around proteins.
• Histone
– protein molecules around which DNA is tightly coiled
into chromatin.
• Replication
– the copying process by which a cell duplicates its DNA.
• DNA polymerase
– the enzyme involved in DNA replication that joins
individual nucleotides to produce a DNA molecule.
MACROMOLECULE REVIEW
NUCLEIC ACIDS– DNA and RNA
nucleic acids store and transmit hereditary, or
genetic, information.
MACROMOLECULE REVIEW
CARBOHYDRATES- Sugars and Starches
Living things use carbohydrates as their main
source of energy (short term energy source)
Plants use them for structural purposes.
___:____:___ ratio
1:2:1 ratio C6H12O6
Macromolecule Test
CARBOHYDRATES
REAGANT
• Simple Sugars Benedict’s
+ COLOR
Orange
• Starch
Black/ Brown
Iodine (Lugols)
MACROMOLECULE REVIEW
LIPIDS- fats, oils, waxes, & steriods
Lipids can be used to store energy (long
term). They also make up an important part of
the cell membrane (phospholipid bilayer).
Macromolecule Test
LIPIDS
REAGANT
+ COLOR
Sudan
Red
*also the brown paper bag test
MACROMOLECULE REVIEW
PROTEINS- made up of amino acids
Some proteins control the rate of reactions
and regulate cell processes (enzymes). Some are
used to form bones and muscles. Others
transport substances into or out of the cells or
help to fight disease.
Macromolecule Test
PROTEINS
Reagant
Buirets
+ Color
Violet
Bell Work 2-25-16
1. During DNA _____________, the chromosomes
are duplicated (or copied).
REPLICATION
2. During ___________, a strand of DNA is used
as the template to make RNA.
TRANSCRIPTION
3. During ___________, the information from
mRNA is used (along with rRNA and tRNA) to
produce proteins.
TRANSLATION
DNA
DNA (deoxyribonucleic acid) is a nucleic acid
– It is a long molecule made up of units called
nucleotides
– Nucleotides are made up of three parts:
a 5-carbon sugar (deoxyribose), a phosphate
group, & a nitrogenous base
Base Pairs
o There are four nitrogenous bases for DNA:
adenine - thymine, cytosine – guanine
Duplicating DNA
Before a cell divides, it duplicates its DNA in a
copying process called replication.
• During which phase of the cell cycle is the
DNA replicated?
– Interphase, during the S phase
• DNA replication is carried out by a series of
enzymes. These enzymes “unzip” a molecule
of DNA. The principal enzyme involved is
called DNA polymerase
RNA
• RNA (Ribonucleic acid) is a nucleic acid
• RNA also consists of a long chain of nucleotides
There are three main differences between RNA and DNA
• The sugar in RNA is ribose instead of deoxyribose
• RNA is generally single-stranded, rather than double
stranded
• RNA contains uracil in place of thymine
Types of RNA
RNA’s main job is PROTEIN SYNTHESIS
(assembly of amino acids into proteins)
• The RNA molecules that carry copies of these
instructions are known as messenger RNA (mRNA)
• Proteins are assembled on ribosomes as well as a
form of RNA, known as ribosomal RNA. (rRNA).
• A third type of RNA tranfers each amino acid to the
ribosome as it is specified by coded messages in
mRNA. These are known as transfer RNA (tRNA).
The 3 types of RNA
Transcription
RNA molecules are produced by copying part
of the nucleotide sequence of DNA into
complementary sequences in RNA, a process
known as TRANSCRIPTION & requires an enzyme
known as RNA polymerase.
During Transcription, RNA polymerase uses
one strand of DNA as a template from which
nucleotides are assembled into a strand of RNA.
RNA editing
The DNA of eukaryotic genes contains
sequences of nucleotides called introns, that are
not involved in the coding for proteins.
The DNA sequences that code for proteins are
called exons, because they are “expressed” in
the synthesis of proteins.
The introns are cut out of the RNA molecule and
the exons are spliced together (Fig. 12-15) 302
Introns & Exons
Translation
The sequence of nucleotide bases in an mRNA
(messanger RNA) molecule serve as instructions
for the order in which amino acids should be
joined together to form a polypeptide.
The decoding of an mRNA message into a
polypeptide chain (protein) is known as
translation.
Transcription & Translation
Mutations
Now and then cells make mistakes in copying
their own DNA. Mutations are changes in the
genetic material.
• Mutations that produce changes in a single
gene are known as gene mutations.
• Those that produce changes in whole
chromosomes are known as chromosomal
mutations.
Mutations
Gene mutations involving changes in one or a few
nucleotides are known as point mutations, because
they occur at a single point in the DNA sequence.
The genetic code is read in three-base codons. If a
nucleotide is added or deleted, the bases are still
read in groups of three, but now these groupings
are shifted for every codon that follows. Changes
like these are called frameshift mutations because
they shift the reading frame.
Chromosomal Mutations
Deletions involve the loss of all or
part of a chromosome.
Duplications produce extra copies
of parts of a chromosome.
Inversions reverse the direction of
parts of a chromosome.
Translocations occur when part of
one of the chromosome breaks off
and attaches to another
Significance of Mutations
Many mutations have little to no effect.
Others that cause drastic changes in protein structure or
gene activity can be disrupt normal biological activity and
may result in genetic disorders.
Harmful mutations in body cells cause many forms of
cancer. Mutations in the cells that produce gametes can
be passed on to offspring.
For example, when a complete set of chromosomes
fails to separate during Meiosis, the gametes that result
may produce triploid (3N) or tetraploid (4N) organisms.
The condition in which an organism has extra sets of
chromosomes is called POLYPOIDY.
Quiz Tomorrow
Macromolecules & Ch. 12 Sections 1-4
Nucleic Acids, Carbohydrates, Lipids, Proteins
DNA, DNA replication, RNA, Transciption,
Translation, Base pairing, and Mutations
Kahoot Review  Get Your Cell Phones Out
12-3 Key Concepts
• There are three main types of RNA: messanger
RNA, ribosomal RNA, transfer RNA.
• During transcription, RNA polymerase binds to
DNA and separates DNA strands. RNA
polymerase then uses one strand of DNA as a
template from which nucleotides are
assembled into a strand of RNA.
• During translation, the cell uses information
from messanger RNA to produce proteins.
12-3 vocabulary
• Gene
– - a sequence of DNA that codes for a protein and thus
determines a trait.
• Messanger RNA
– (mRNA)- RNA molecule that carries copies of instructions for the
assembly of amino acids into proteins from DNA to the rest of
the cell.
• Ribosomal RNA
– (rRNA)- type of RNA that makes up the major part of
ribosomes.
• Transfer RNA
– (tRNA)- type of RNA molecule that transfers amino acids to
ribosomes during protein synthesis.
12-3 Vocabulary
• Transcription
– the process in which part of the nucleotide sequence of
DNA is copied into a complementary sequence in RNA.
• RNA polymerase
– enzyme similar to DNA polymerase that binds to DNA and
separates the DNA strands during transcription.
• Promotor
– region of DNA that indicates to an enzyme where to bind
to make RNA.
• Intron
– sequence of DNA that is not involved in coding for a
protein.
12-3 Vocabulary
• Exon
– expressed sequences of DNA; codes for a protein
• Codon
– three-nucleotide sequence on messenger RNA that
codes for a single amino acid.
• Translation
– decoding of a mRNA message into a polypeptide
chain.
• Anticodon
– group of three bases on a tRNA molecule that are
complementary to an mRNA codon.
12-4 Vocabulary
Mutation- change in a DNA sequence that affects genetic
information.
point mutation- gene mutation involving changes in one or a
few nucleotides.
frameshift mutation- mutation that shifts the “reading” frame
of the genetic message by inserting or deleting a nucleotide.
Polyploidy- condition in which an organism has extra sets of
chromosomes.
Base pairs of DNA vs. RNA
Base pairs of DNA
Adenine & Thymine
Base pairs of RNA
Adenine & Uracil
Cytosine & Guanine
Cytosine & Guanine
CODONS
Proteins are made by joining amino acids into
long chains called polypeptides. Each
polypeptide contains a combination of any or all
of the 20 different amino acids.
Remember: Codons are three consecutive
nucleotides that specify a single amino acid.
Amino Acids build proteins.
Fig 12-17 p.303 Start from the Middle & Work Outwards