Wake-up

Wake-up

1. Explain the difference between a plant cell and an animal cell.

2. Write down the summative formula for BOTH photosynthesis and cellular respiration. How do they compare?

AVID Review #3

Christopherson

Structure and Components of the Nucleus

Nucleolus

DNA(Gray lines)

Nucleus

DNA: Deoxyribonucleic

Acid

Structure of a Nucleotide

1. Phosphate

2. Deoxyribose

3. Nitrogen Base

a. Adenineb. Thyminec. Cytosine

d. Guanine

DNA Discovery: Chargaff

He spent time examining the nitrogen bases

of different organisms

He found that there were equal amounts of Adenine and Thymine; also equal amounts of

Guanine and Cytosine

DNA Discovery: Watson and CrickUsed their own data and information collected by the other scientists to discover the shape of

DNA

Structure of DNA

Deoxyribose

NitrogenBase

Phosphate

Matching Strands of DNA

A T G C T T A C A T G C T A C T T A A C

Remember that A=T and G=C

T A C G A A T G T A C G A T G A A T T G

Cell

Nucleus

Chromosome: DNA that is completely coiled-up; condensed

Chromatin: Loose mass

of DNA

DNA winds around Histones; similar to spoolsDNA keeps winding

up; tighter and tighter

DNA Replication: Purpose

To make copies of DNA

Replication: Why?

Growth/Development

Replication: Why?Replace old cells

Replication: Why?

Asexual Reproduction: Offspring is an identical copy of the parent

PhosphateDeoxyribose

Nitrogen Base

Double Helix

Steps in DNA Replication #1

DNA Helicase (enzyme) attaches to DNA strand.

Helicase unwinds DNA by breaking the hydrogen bonds holding together the bases

PhosphateDeoxyribose

Nitrogen Base

Helicase Helicase

Double Helix


DNA Polymerase (enzyme) attaches to exposed strands.

It adds matching nucleotides.

It also proofreads its work to make sure there is no mistakes.

DNA Polymerase

C

T

G

A

Nucleotide

DNA Backbone


Produce 2 identical

strands of DNA

Old OldNew New

Centromere: Central part of a

chromosome

Chromatid(s): Wound up strand of DNA; two strands are sister

chromatids

When a chromosomes is shaped like an “X”, DNA

has been replicated (copied)

Chromosome

InterphasePurpose: Cell Preparation; getting the

cell ready to divideStages - (a) G1 (1st growth): Cell starts to

make more organelles for new cell Stages – (b) S (Synthesis): DNA is

replicated in the nucleus

Stages – (c) G2 (2nd growth): Cell completes the growth; organelles and

cytoplasm

Is this a Plant cell or Animal cell?

Mitosis: Purpose

Divide the DNA in the nucleus

Mitosis: Prophase

a. The membrane of the nucleus disappearsb. Chromatin (loose DNA) winds up into

chromosomes (condensed DNA)

c. Spindle fibers appear

Mitosis: MetaphaseThe spindle fibers attach to the

centromeres and pull the chromosomes to the middle of the cell

Mitosis: AnaphaseThe sister chromatids are separated and

pulled to opposite ends of the cell

Mitosis: Telophase

a. The nucleus reappearsb. DNA uncoils/unwinds; chromosome to chromatin

c. Spindle fibers disappear

Cytokinesis

Division of the cytoplasm and

organelles

Produces two identical CELLS

What is a Body Cell?

All the cells that make up the “body” of an organism.

All organisms have chromosomes (condensed DNA); Also a specific number

Total Number of Chromosomes in a Human Body Cell

Location of the Cell Cycle

Within an organisms body cells

1st Step of the Cell Cycle

Interphase: Cell prepares to divide by

making more organelles and

cytoplasm; Replicates DNA

2nd Step of the Cell Cycle

Mitosis: The replicated DNA

is separated

Made up of PMAT

3rd Step of the Cell Cycle

Cytokinesis: The cell divides the organelles and cytoplasm into the new cell

End Result of the Cell Cycle

Two identical cells with the same number of chromosomes

Interphase MitosisCytokinesis

If an organism has 50

chromosomes and it undergoes

mitosis, how many

chromosomes will be present in

the new cells?

If an organisms diploid number chromosome is 100, how many chromosomes will be

present in the new cells?

If an organism has 18

chromosomes and it undergoes

mitosis, how many

chromosomes will be present in

the new cells?

If an organisms diploid number chromosome is 134,568, how

many chromosomes

will be present in the new cells?

134, 568

What is a GENE?

Instruction manual for our body

Portion of DNA that “codes” (has

directions) for a trait

What is a TRAIT?A trait is a genetically determined characteristic

Where is a Gene?

•Within DNA

•The nitrogen bases spell out

the instructions.

RNARibonucleic

Acid

Make up of Nucleotides

Contains Phosphorus

RNA Nucleotide

A

BC

Phosphate

Ribose

Nitrogen Base

GuanineCytosineAdenine

Uracil

Types of RNA

Messenger RNA

Nickname: mRNA

Made up of ONE strand

of nucleotides

mRNA FunctionCopy a message from a gene on DNA

DNA

mRNA

Types of RNA

Transfer RNA

Nickname: tRNA

Made up of ONE strand of nucleotides and a amino acid

tRNA FunctionCarries amino acids to mRNA

mRNA

Amino Acids

DNA versus RNA: # of Strands

1 strand2 strands

DNA versus RNA: Sugar

Deoxyribose Ribose

DNA versus RNA: Bonds with Adenine

Adenine Thymine Adenine Uracil

DNA RNA

Brief Summary of Transcription

Make mRNA from a gene on DNA

Location of Transcription

Nucleus

Process of Transcription

T A C G C G C C T A G G A T T A G TA T G C G C G G A T C C T A A T C A

DNA Backbone Nitrogen Bases

Choose a gene that needs to be “read” or copied

RNA Polymerase attaches to DNA and

breaks Hydrogen bonds; splitting DNA

RNA Polymerase


T A C G C G C C T A G G A T T A G T

A T G C G C G G A T C C T A A T C A

DNA BackboneNitrogen Bases

DNA

A U G C G C G G A U C C U A A T C A

RNA polymerase adds matching nucleotides to exposed DNA strand

mRNA

RNA Polymerase


DNA is split apart; separated


T A C G C G C C T A G G A T T A G TA T G C G C G G A T C C T A A T C A

DNA BackboneNitrogen Bases

DNA

A U G C G C G G A U C C U A A U C A mRNA

RNA Polymerase

RNA Polymerase leaves

A U G C G C G G A U C C U A A U C A


mRNA leaves the nucleusDNA recombines

mRNA

Transcribe the following

TAC CAC AAT CTC GCA GAT TTA GCA AGTDNA

AUG GUG UUA GAG CGU CUA AAU CGU UCAmRNA

Summary of Translation

Protein is made

from mRNA strand

Location of Translation

rRNA

Ribosome

AUG CGC GGA UCC UCA UAA mRNA

UAC AGU AUUAGGCCUGCG

Met Ser StopSerGlyArg

Three base sequence in mRNA is called a codonCodon

Ribosome

A ribosome attaches to mRNAA tRNA anticodon matches with a mRNA codon

Anticodon

Codon

Another tRNA anticodon matches with a codon rRNA forms a peptide bond between theamino acids

Peptide Bond

First tRNA leaves and the ribosome shifts. A new tRNA fills empty space.

Another peptide bond is formed and the process continues

A protein has been made

ProteinAmino acid

TAC GGA CAT GAC GGG AAA ATT

AUG CCU GUA CUG CCC UUU UAA

Met – Pro – Val – Leu – Pro – Phe - Met

DNA

mRNA

Amino Acid

MutationsMutations

What is a mutation?

Change in the DNA nitrogen base

sequence of a gene

How do Mutations Occur?

Errors in DNA Replication

Replication

How do Mutations Occur?

Damaged DNA caused by

agents such as sunlight, smoke,

radiation

Category of Mutation: Point Change in one base of the DNA sequence.

Original: The fat cat ate the wee rat

Point mutation: The fat hat ate the wee rat

Sickle Cell Anemia: Point Mutation

Category of Mutation: Frameshift Addition or deletion of a DNA base resulting

in a different sequence of DNA.

Original: The fat cat ate the wee rat

Frameshift mutation: The fat ata tet hew eer at

Example of Frameshift Mutation: Tay Sachs

Tay Sachs Disease: Frameshift Mutation

Type of Mutations: Missense Change in one base of the DNA sequence

which causes a change in amino acid.

Type of Mutations: Nonsense Change in one base of the DNA sequence

which codes for a STOP codon

Type of Mutations: SilentChange in one base of the DNA sequence which

has no effect on the amino acid sequence

Type of Mutations: InsertionAddition of one or more bases into a DNA

sequence

Type of Mutations: DeletionThe removal of one or more bases in DNA

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