Download Unit 04 Lecture Notes - Roderick Anatomy and Physiology

Unit 04
Cellular Metabolism
Latin Word
Form
Meaning
De-
Prefix
Opposite
Hydro
Root
water
Lyse
Root
To break
-sis
Suffix
Process off
Ana
Prefix
Build
Cata
Prefix
Break
-ism
suffix
An action or result
Synth
Root
To create
-ase
Suffix
Type of enzyme
Co-
Prefix
Together
Glyco
Root
Sugar
tri-
Prefix
Three
Anti-
Prefix
Against/opposite
Covered in this Unit
•
•
•
•
•
•
•
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4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
Introduction
Metabolic Reactions
Control of Metabolic Reactions
Energy for Metabolic Reactions
Metabolic Pathways
Nucleic Acids
Protein Synthesis
DNA Replication
4.1 Objectives
• Cells require information and energy
• An enzyme is a special type of protein that
controls chemical reactions
• Genes carry the information needed to create
proteins and enzymes
4.2 Objective
• I can differentiate between Anabolism and Catabolism
• I can explain how Dehydration Synthesis works
• I can explain why Dehydration synthesis is an anabolic
reaction
• I can explain how Hydrolysis works
• I can explain why Hydrolysis is an anabolic reaction
• I understand how Dehydration synthesis and Hydrolysis
work together to build and break down carbohydrates,
proteins and nucleic acids.
4.3 Objectives
• I can describe the general characteristics of an Enzyme
(structure and function)
• I can explain how enzymes and substrates interact to
speed up chemical reactions.
• I can explain how enzymes and substrates are specific.
• I can list 4 factors that alter (denature) enzymes
• I can give examples of cofactors and describe its
function.
4.4 Objectives
• I know what energy is
• I know the 9 different forms energy can take
• I know where chemical energy is stored and
how it can be released.
• I can describe how oxidation is different from
burning.
4.4 Objectives Cont.
• I know the 3 reactions that make up cellular respiration.
• I know the general characteristics of Adenosine triphosphate (ATP)
• I know the difference between Anaerobic and Aerobic Respiration
• I know the where glycolysis occurs, its input and outputs and whether or
not it is anaerobic or aerobic.
• I know the where the citric acid cycle occurs, its input and outputs and
whether or not it is anaerobic or aerobic.
• I know where the electron transport chain occurs, its input and outputs
and whether or not it is anaerobic.
• I can explain what the term oxidative phosphorylation means.
4.5 Objectives
• I can explain what a metabolic pathway is.
• I can describe how a rate-limiting enzyme can control a
chemical pathway.
• I know that the rate-limiting enzyme is the first enzyme
in a series.
• I can list and describe the Lipid metabolic pathway for
energy
• I can list and describe the steps in the protein metabolic
pathway for energy
4.6 Objectives
• I know what DNA is and why it is important to cells.
• I know can explain how information is transmitted
from parents to offspring.
• I know all DNA in a cell is known as a person’s
genome
• I can draw and describe the physical structure of a
DNA molecule
• I understand the concept of base pairing.
4.7 Objectives
• I know that the genetic code stores the information
needed by ribosomes to create proteins.
• I can explain how information is transmitted from
parents to offspring.
• I know the difference between DNA and RNA.
• I can explain the process of Transcription. (Where,
what molecules are involved, why it’s important)
• I can explain the process of Translation. (Where, what
molecules are involved and why it’s important)
4.8 Objectives
• I can explain the process of DNA replication
(when it happens, why it happens, how it
happens.)
4.1 Introduction
4.1 Cellular Energy
• All cells require ENERGY and INFORMATION.
• Energy is required to perform chemical reactions.
• The cell’s reactions break down NUTRIENTS to
release ENERGY.
• Information is required to make proteins from
genes. Especially Enzymes.
• Reactions are controlled by proteins called
ENZYMES
Check for Understanding
• What two things do cells need?
• What is a special protein that helps control
chemical reactions?
• What carries the information the cell needs to
create proteins.
4.2 Metabolic Reactions
4.2 Metabolic Reactions
• Two major types of metabolic reactions:
Anabolism and Catabolism
4.2 Metabolic Reactions:
Anabolism
• Anabolism is the BUILD UP of LARGER
molecules from SMALLER ones.
• Cells join two simple sugar molecules called
MONOSACCHARIDES into a larger molecule
called a DISACCHARIDE
Glucose
Fructose
Disaccharide
CH2OH
H H
HO OH
H
O
H
H OH
OH
4.2 Metabolic Reactions:
Anabolism
• When these two simple sugars combine, a
WATER molecule is RELEASED WHICH IS WHY
THE ANABOLIC PROCESS IS CALLED
DEHYDRATION SYNTHESIS
H
H
OH HO
Disaccharide
4.2 Metabolic Reactions:
Anabolism
Amino Acids to Proteins
Monosaccharides to Di or Polysaccharides
Nucleotides to Nucleic Acids
Glycerol Head and Fatty
Acid Chains
OH = Hydroxyl Group
Monosaccharide
Polysaccharide: Glycogen
Peptide Bond created by
Dehydration Synthesis
Lipid created by Dehydration
Synthesis
Nucleic Acid Created by
Dehydration Synthesis
Draw Figure 4.1: Dehydration
Synthesis
O
4.2 Metabolic Reactions:
Catabolism
• Catabolism BREAKS DOWN larger molecules
into SMALLER ones.
Glucose
Fructose
4.2 Metabolic Reactions:
Catabolism
• The process that breaks down carbohydrates
by splitting a LARGE molecule is called
O
HYDROLYSIS.
H H
H
H
O
4.2 Metabolic Reactions:
Catabolism
• Hydrolysis occurs primarily during DIGESTION.
Draw Figure 4.1: Hydrolysis
O
Check for Understanding
• Anabolism = _______________ molecules
• Catabolism = ________________molecules.
• Dehydration synthesis is an example of ___________________.
• Hydrolysis is an example of ________________.
• How does dehydration synthesis work?
• How does hydrolysis work?
• If I wanted to build a polymer what chemical reaction would I use?
• If I wanted to break down a polymer, say during digestion, what chemical reaction would I
use?
• Removing a water = _______________________.
• Adding a water = _________________________.
4.3 Control of Metabolic
Reactions
4.3 Control of Metabolic
Reactions
• Since the temperature in cells are usually too
MILD to adequately promote reactions,
ENZYMES make them possible.
4.3 Control of Metabolic
Reactions
• Enyzmes work by LOWERING the amount of
ENERGY called ACTIVATION ENERGY, required
to start these reactions
4.3 Control of Metabolic
Reactions
4.3 Control of Metabolic
Reactions
• Each enzyme is very specific and can only act
on one particular chemical molecule, called a
SUBSTRATE.
• The ability to identify it’s SUBSTRATE depends
on the SHAPE of the enzyme molecule.
• Where the enzyme-substrate complex meet is
called the ACTIVE SITE
Draw Figure 4.4
Denaturation of Protein
Cofactor/Coenzyme
4.3 Control of Metabolic
Reactions
• When exposed to heat, radiation, electricity,
etc., an enzyme shape can twist and that is
called DENATURATION
• Some ENZYMES are INACTIVE until they
combine with a COFACTOR or a COENZYME
Check for understanding
• Can you label the parts of the enzymesubstrate complex.
• How do enzymes speed up chemical reactions?
• What does it mean to be specific? (think lock
and key)
• What are four things that can denature a
protein?
• How do cofactors and enzymes interact?
4.4 Energy for Metabolic
Reactions
4.4 Energy for Metabolic
Reactions
• Energy is the ability to do WORK.
• Forms of energy include:
1.
2.
3.
4.
5.
6.
7.
8.
9.
KINETIC
POTENTIAL
MECHANICAL
THERMAL
CHEMICAL
ELECTRICAL
SOUND
LIGHT
NUCLEAR
4.4 Energy for Metabolic
Reactions
• Chemical Energy is stored in the BONDS
between atoms and molecules and IS
RELEASED when these bond are BROKEN.
• The process that cells use to break down
GLUCOSE molecules is called OXIDATION.
4.4 Energy for Metabolic
Reactions
Burning
• Requires large
amount of energy to
get started.
• Energy released as
heat and light
Oxidation
• Enzymes reduce amount of
energy needed (coupons)
• Energy carrying molecules
(NADH and FAD) capture
about ½ of the energy and
use it to make new
chemical bonds.
•
The rest is released as
heat
Cellular Respiration
• The process that cells use to break down
GLUCOSE molecules is called CELLULAR
RESPIRATION.
• The main purpose of cellular respiration is to
release the energy stored in the chemical
bonds of glucose and use that energy to create
ATP
4.4 Energy for Metabolic
Reactions
ATP – The Battery of Life
Students will be able to describe the structure and
properties of ATP and how it provides energy for the cell.
ATP
• *ATP = Adenosine triphosphate
• *ATP is a molecule that acts like a charged
chemical battery. Our body uses the energy in
ATP to power itself, and then recharges it.
Tri phosphate = three phosphates
Adenosine = adenine + ribose
ATP
• The Energy our body uses is stored in the
bond between the 2nd and 3rd phosphate
Using ATP
 When our body needs energy, it breaks the bond between
the 3rd and 2nd phosphate and becomes Adenosine
Diphosphate.
Energy
ATP  ADP + Pi + Energy
•
ADP
*ADP = Adenosine Diphosphate
*ADP is a molecule that acts like an uncharged
chemical battery. Our body needs to supply energy
from the sun or food to recharge it into ATP
Energy
Diphosphate = 2 phosphates
Adenosine = adenine + ribose
ATP and ADP
ADP
ATP
• Charged Battery
• Not Charged Battery
Tri phosphate = three phosphates
Diphosphate = 2 phosphates
Adenosine = adenine + ribose
Adenosine = adenine + ribose
Charging ADP into ATP
• Attaching a third phosphate to ADP
requires energy. Living things get this
energy from the sun or from food.
ADP + Pi + Energy  ATP
ATP and ADP Cycle
• ATP and ADP cycle - the process of cells
breaking down ATP into ADP for energy, and
then recharging ADP into ATP using energy
from the sun or from food.
Charging up
energy
Energy from
Sunlight or
Food
ATP
Charged Battery
ATP  ADP + Pi + Energy
ADP
Uncharged Battery
ADP + Pi + Energy  ATP
Using up
energy
Energy used by
the cell
Energy
ADP + Pi + Energy  ATP
ATP
Charged Battery
Charging up
energy
Using up
energy
Energy used by
the cell
Energy from
Sunlight or Food
Energy
ADP
Uncharged Battery
ADP + Pi + Energy  ATP
ATP
Charged Battery
ADP + Pi + Energy  ATP
Energy used by
the cell
Energy from
Sunlight or Food
ADP
Uncharged Battery
ADP + Pi + Energy  ATP
ATP Production
• The majority of ATP production occurs in the
Mitochondria.
The Mitochondria
Students will be able to label and know the parts of the
mitochondria
Mitochondria
• An organelle found in eukaryotic plant and animal
cells.
• Creates energy by breaking down sugar into ATP.
Mitochondria in cells
Anatomy of a Mitochondria
Anatomy of a Mitochondria
• Outer Membrane
• Membrane created after endosymbiosis
• Inner Membrane
• Original membrane before endosymbiosis
• *Matrix
• Fluid that fills the mitochondria
• *Cristae
• Folds of the inner membrane
Phases of Cellular Respiration
Students will be able to label and know the parts of the
mitochondria
Cellular Respiration
• There are two types of cellular respiration:
• Anaerobic
• No oxygen is required
• Aerobic
• Oxygen is required
Cellular Respiration
• Cellular Respiration occurs in three phases:
• Glycolysis
• Occurs in cytoplasm
• Anaerobic
• Krebs’s/Citric Acid Cycle
• Occurs in mitochondria
• Aerobic
• Electron Transport Chain
• Occurs in mitochondria
• Aerobic
Phase 1: Glycolysis
• Glycolysis = Splitting or Breaking Glucose
• It costs 2 ATP to break Glucose
• 6 carbons sugar GLUCOSE is broken down into
2 3-Carbon Pyruvic Acid Molecules
• Breaking Glucose also releases 4 ATP and High
energy electrons.
Electron carriers
• Oxidation: When a molecule loses electrons
during a chemical reaction.
Electron carriers
• Molecules called Electron carriers, catch the
electrons released during glycolysis and take
them to the electron transport chain.
• The two electron carriers used in Cellular
respiration are
• NAD+  NADH
• FAD  FADH2
NAD+
e
e
NAD
NADH
NAD-+
H+
Electron Carrier
e
NAD+
Without Electrons
e
H+
NADH
With Electrons
FAD
e
e
H+
H+
--2 FAD
FADH
2
FAD
e
e
H+
H+
FAD
FADH2
Without Electrons
With Electrons
Glycolysis: The process of breaking sugar
Occurs in the cytoplasm.
ANAEROBIC
AT
ADP
AT
ADP
P
P
Glucose
• Input
• 1 glucose molecule
• 2 NAD+
• 2 ATP
NADH
• Output
• 4 ATP
• 2 NADH
• 2 Pyruvic Acids
NAD+
NAD+
ATP
ATP
ATP
ATP
4 ATP
NADH
2 NADH
Pyruvic
Acid
Pyruvic
Acid
2 Pyruvic Acids
Where Does Everything Go?
• ATP = stays in cytoplasm
• Pyruvates= goes to the matrix of the mitochondria
• NADH = goes to the matrix of the mitochondria
ATP
ATP
ATP
ATP
Cytoplasm
Pyruvic
Acid
Matrix of
Pyruvic
Acid
NADH
Matrix of
NADH
How Much ATP is made?
• Glycolysis spends:
• Glycolysis produces:
ATP
Total Net gain of glycolysis is
ATP
-2 ATP
4
2
Krebs’s/Citri
c Acid Cycle
Pyruvic
Acid
Acetyl
CoA
Coenzyme
The 3-Carbon PYRUVIC ACID enter
THE MITOCHONDRIA. Each loses a
CARBON and combines with a
coenzyme to make ACETYL
COENZYME A.
Carbon Dioxide
CO2
Carbon Dioxide
CO2
A coenzyme changes
Pyruvic Acid into
Acetyl Coenzyme A and
2 Carbon Dioxides are
released.
• Acetyl CoA combines with 4-carbon
oxaloacetic acid to form 6 Carbon CITRIC acid.
Each turn removes 2 Carbons as CO2 and one
ATP
Krebs’s/Citric
Acid Cycle
Input:
Output:
2 Acetyl CoA 6 Carbon Dioxides (CO2)
8 NADH
2 ATP
2 FADH2
Acetyl
Co
CoAA
Occurs in the Matrix of the
Mitochondria
AEROBIC
NADH
NADH
Carbon Dioxide
CO2
Carbon Dioxide
CO2
NADH
NADH
NADH
FADH2
NADH
Carbon Dioxide
CO2
FADH2
ATP
ATP
NADH
NADH
Carbon Dioxide
CO2
Exhaled by body
Output
Input:
2 Acetyl CoA
6 Carbon Dioxide
8 NADH
2 FADH2
2 ATP
Acetyl
Co A
NADH
FADH2
Krebs Cycle
Acetyl
Co A
ATP
Back to the
cytoplasm
Electron Transport
Chain
How much ATP is made?
• Glycolysis Net Gain:
• Krebs Cycle produces:
2 ATP
2 ATP
Total ATP:
4 ATP
Electron Transport Chain
• Input
• FADH2
• NADH
• Output
•
•
•
•
6 H2O
32-34 ATP
NAD+
FAD
Occurs in the Cristae (inner membrane) of
the Mitochondria
AEROBIC
Electron Transport Chain
1. NADH and FADH2 lose their Hydrogen Ions
and Electrons and return to NAD+ and FAD
2. The electrons from FADH2 and NADH travel
through the electron transport chain.
1.
This provides energy that pulls hydrogen ions out
of the matrix.
Electron Transport Chain
3. The hydrogen ions return back to the matrix
via ATP synthase.
1.
Every time a hydrogen ion goes through ATP
Synthase an ADP and a phosphate combine to
create an ATP.
4. The electrons combine with two hydrogen
ions and an oxygen to create water.
Space in between the inner and outer membrane
H+
H+
H+
H+
H+
ELECTRON
H+
H+
ATP
SYNTHASE
Chain
Transport
H+
ATP
ATP
ATP
NADH
NAD+
H+
H+
Matrix
H+ H+
FADH2
H+
H
Water
H+
H+
H+
H+
ATP SYNTHASE
• https://www.youtube.com/watch?v=3y1dO4nNaKY
What happens to
the electrons?
O + 2e- + 2H+  H2O
Oxygen + 2 electrons +2 Hydrogen Ions 
e- e-
Water
ee-
e-
O
e-
e-
e-
e-
e-
H
H
Where does everything go?
• NAD+ and FAD go back to the cytoplasm and the matrix
to be recharged into NADH and FADH2.
• ATP returns to the cytoplasm to be used.
• Water exits the body.
H
O
ATP
H
Out of the body
Cytoplasm
NAD+
FAD
Matrix and or Cytoplasm
How much ATP is made?
• Glycolysis Net Gain:
• Krebs Cycle produces:
• Electron Transport Chain produces:
2 ATP
2 ATP
32-34 ATP
• Total ATP:
36-38 ATP
4.5 Metabolic
Pathways
Metabolic Pathways
• A sequence of enzyme-controlled reactions is
called a METABOLIC PATHWAY.
• The rate of a metabolic pathway is determined
by a REGULATORY ENZYME.
• The first enzyme in a series is called the RATE
LIMITING ENZYME
Carbohydrate Pathway
(cellular respiration)
• Cellular Respiration – The breakdown of glucose to release
energy in the form of ATP (Adenosine Triphosphate)
• Step 1 (Glycolysis)
• Anaerobic – no oxygen
• Occurs in Cytosol
• Starts:
• Glucose + 2 ATP  Glycolysis  Pyruvic acid (pyruvate)
• Ends
4 ATP (2 Net ATP)
Electrons carried by NADH
Carbohydrate Pathway
(cellular respiration)
• Step 2 (Krebs Cycle)
• Occurs in Mitochondria
• Aerobic – Oxygen present
• Starts
2 CO2
4 CO2
• Pyruvic Acid (Pyruvate)  Acetyl CoA  Citric Acid Cycle
• Ends
2ATP
Electrons carried by 8NADH
and 2 FADH2
Carbohydrate Pathway
(cellular respiration)
• Step 3 (Electron Transport Chain)
• Occurs in Mitochondria
• Aerobic – Oxygen present
• Starts
• Electron Carriers (NADH + FADH2)  Electron Transport Chain Carriers
(NADH and FADH2)
• Ends
32 - 34ATP
6H2O
Protein Pathway
Proteins
(Hydrolysis)
Amino Acids
Pyruvic Acid
Acetyl CoA
Krebs’s/Citric Acid
Cycle
Electron Transport
Chain
2 CO2
4 CO2
2 ATP
Electrons carried by 8NADH and 2 FADH2
32ATP
6H2O
Lipid Pathway
Lipids
(Hydrolysis)
Glycerol
Pyruvic
Acid
Fatty Acids
Acetyl CoA
4CO2
2CO2
Krebs’s Citric Acid Cycle
Acetyl CoA
Krebs’s Citric Acid Cycle
4CO2
2ATP
Electrons carried
by 8NADH and 2
FADH2
Electron Transport
Chain
2CO2
Electrons
carried by
8NADH and 2
FADH2
Electron Transport Chain
32ATP
32ATP
6H2O
2ATP
6H2O
Proteins
Carbohydrates
Amino
Acids
Glucose
Pyruvic Acid
Carbohydrates,
Proteins, and Lipids
can be changed into
Pyruvic Acid.
Once changed to
Pyruvic Acid – the
metabolic pathway is
identical for
proteins,
carbohydrates, and
lipids.
Acetyl Group
Krebs’s Citric Acid
Cycle
Electron Transport
Chain
Lipids
Glycerol Fatty Acid
Head
Chain
4.6 Nucleic Acids
Listen
Nucleic Acids
• Nucleic Acids are a macromolecule.
• Monomer: Nucleotide
• Polymer: Nucleic Acid
• The nucleic acids most important to life are
DNA and RNA
Listen
DNA Nucleotide Structure
Phosphate
Sugar
Base
Write
4.6 Nucleic Acids
• DNA or DEOXYRIBO NUCLEIC ACID contains the
instruction cells need to SYNTHESIZE enzymes
and proteins.
• Genetic information is passed from parents to
child in the form of DNA MOLECULES from
parent’s SEX CELLS.
Write
4.6 Nucleic Acids
• Directions for making particular PROTEINS are
called GENES.
• GENES instruct CELLS to synthesize the
PROTEINS that control METABOLIC pathways.
• A GENOME constitutes all of the DNA in a cell.
Phosphate
Phosphate
Phosphate
Deoxyribose
Deoxyribose
Deoxyribose
T
G
Deoxyribose
C
A
Phosphate
Listen
DNA Nucleotide Structure
A denine
Phosphate
T hymine
Deoxyribose
Base
C ytosine
Guanine
Listen
Listen
Listen
DNA Structure
Backbone
Backbone
Middle
A
T
C
A
G
T
C
G
Listen
DNA Structure
Backbone
Listen
Backbone
Middle
A
T
C
A
G
T
C
G
Listen
Write
4.6 Nucleic Acids
• A DNA structure looks like a ladder in which the uprights represent
the SUGAR and PHOSPHATE backbones of the two.
• The organic base of a DNA Nucleotide can be:
1. ADENINE, 2. THYMINE, 3. CYTOSINE, 4. GUANINE
• ADENINE will bond only to a THYMINE, and a CYTOSINE, will only
bond to a GUANINE.
• This is called BASE PAIRING
• DNA twists to make a DOUBLE HELIX
Listen
RNA Nucleotide Structure
A denine
Phosphate
Uracil
Ribose
Base
C ytosine
Guanine
Listen
mRNA
• Messenger RNA
Listen
tRNA
• Transfer RNA
Listen
rRNA
• Ribosomal RNA
RNA Types
RNA Type
Abbreviated
Name
Function
Shape
Location
Messenger RNA mRNA
Copy info from
DNA and
delivers it to
ribosome
Nucleus 
Ribosome
Transfer RNA
Delivers amino
acids to
ribosome
Cytoplasm 
Ribosome
tRNA
Ribosomal RNA rRNA
Part of the
Ribosome
Don’t need to
know.
Ribosome
Write
Write
4.7 Protein Synthesis
Listen
DNA as Information
Listen
Listen
Alphabets and Information
DOG
CAT
APPLE
CAR
GENES
AIRPLANE
SCHOOL
Listen
Listen
Listen
Listen
DNA Alphabet Letters
A
T
G
C
DNA Alphabet Words (Codons)
A T G
A C C
C T G
G G C
Write
Codons
• Words of the DNA language can be found on
mRNA.
• We call these words Codons.
• Codon: three nucleotides (bases) on mRNA
A U G
A U G
G G C
mRNA
C U G
Write
Codons
• DNA also has punctuation.
• Start Codon (AUG) = Tells you when to start.
• Stop Codon = (UAA, UAG, UGA) Tells you when to stop.
A U G
A U G
G G C
mRNA
C U G
Write
Codons
• The sequence of nucleotides (bases)
determines what protein will be made.
A U G
A U G
G G C
mRNA
C U G
Write
CENTRAL DOGMA OF BIOLOGY
Listen
CENTRAL DOGMA OF BIOLOGY
DNA
RNA
Listen
Transcription
DNA
mRNA
DNA
RNA
Polymerase
Listen
Write
TRANSCRIPTION: DNA  RNA
• Transcription: RNA polymerase reads DNA and
copies the information onto an mRNA strand by
base pairing.
• The mRNA leaves the Nucleus and travels to a
Ribosome
Listen
Codons and Anti-Codons
• Transfer RNA delivers amino acids to the
Ribosome, but how do they know which Amino
Acids to transfer?
• They use Anti-Codons
Write
Amino
Acid
An Anti-Codon is 3 nucleotides
(bases) found on a transfer RNA.
A U G
Write
Amino
Acid
Amino
Acid
Amino
Acid
Amino
Acid
U A C U A C C C G G A C
A U G
A U G
G G C
mRNA
C U G
TRANSLATION: RNA  PROTEIN
Write
TRANSCRIPTION: DNA  RNA
• Translation: mRNA moves through the
ribosomes. Anti-codons on tRNA base pair with
codons bringing amino acids to the ribosome.
• The ribosome binds the amino acids together
to create a protein.
Write
DNA REplication
DNA REPLICATION
Listen
Listen
G1 Phase
Telophase
S Phase
DNA
REPLICATIO
N
Anaphase
Metaphase
Prophase
G2 Phase
Write
Write
DNA Replication
• DNA Replication: The process of copying one’s DNA
• DNA is copied in preparation for Mitosis and
Meiosis
• DNA Replication occurs during the S (Synthesis)
phase of the Cell Cycle
Listen
Listen
Listen
Template
Strand
Complimentary Strands
Template
Strand
Template
Strand
Template
Strand
Listen
Listen
Write
DNA Replication
• New strands of DNA splitting the double helix open
and creating a new strand by base pairing.
Listen
Listen
Listen
Listen
Listen
HELICASE
Listen
Listen
Listen
Listen
Listen