Anatomy and Physiology Chapter 4

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Anatomy and Physiology Chapter 4
23 pairs of chromosomes in the human nucleus
Genes
Chromosome
Bases
DNA Strand
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4.1 Introduction

• Cells require energy and information to build
  bodies.
• Cells carry out many reactions of metabolism.
• These reactions break down nutrients to release
  energy.
• Cells carry genetic info.
• Enzyme is a special type of protein that controls
  each reaction of metabolism.

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4.2 Metabolic Reactions

• Metabolic reactions are of two types in
  anabolism reactions, larger molecules are
  constructed from smaller one.
• The process that provides the biochemicals
  required for cell growth and repair is anabolism.
  
• In catabolism reactions, larger molecules are
  broken down.
• The reactions of metabolism are often reversible.
• Which process requires energy? Anabolism Which
  releases energy? Catabolism
• The process of joining two molecules by removing
  water is called dehydration synthesis. A
  by-product of dehydration synthesis is water.
• The process of splitting two molecule by adding
  water is called hydrolysis. Hydrolysis occurs
  during digestion.

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4.3 Control of Metabolic Reactions

• Enzymes control the rates of all the metabolic
  reactions of the cell.
• Enzymes are complex molecule (PROTEIN) that
  function to lower the activation energy of a
  reaction so it may begin and proceed more
  quickly. Because they do this, enzymes are
  called catalysis.
• The substances the enzymes act on are called
  substrate. Each enzyme is specific. Enzymes
  recognize the specific shape of the substrate
  with which they react.

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4.3 Control of Metabolic Reactions continued

• Enzymes are needed to promote metabolic reactions
  in the body because the temperature in cells is
  not high enough to promote the increase in
  chemical reaction rates.
• Very small quantities of enzymes are needed
  because they are not consumed in the metabolic
  reaction they facilitate.
• Enzymes can be denatured (destroyed) by heat and
  radiation, chemicals and extremes of pH, and
  electricity.

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4.4 Energy for Metabolic Reactions

• The form of energy most often used by the body's
  metabolic processes is chemical.
• ATP is Adenosine Triphosphate . It stores the
  energy for every reaction in the body.
• Energy can be mechanical, chemical, and thermal.
• The function of ATP is to store energy in its
  terminal phosphate bond.

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Cellular Respiration

• Is the process that releases the energy in the
  chemical bonds of the energy nutrients and stores
  it in molecules of ATP.
• It has 3 basic stages, each of which have several
  steps and are controlled by many enzymes.
• The first stage does not require oxygen and so is
  said to be anaerobic.
• The other two stages require oxygen and therefore
  are aerobic.

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1st Stage of Respiration

• The first stage of cellular respiration is
  anaerobic and occurs in the cytosol.
• The anaerobic respiration is called glycolysis.
  Where does it take place? cytosol
• What chemical does it start with? glucose
  What chemical does it end
  with? Pyruvic acid
• Are any ATPs formed? 2

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2nd 3rd Stages of Respiration

• The second phase of cellular respiration is
  aerobic and occurs in the mitochondria.
• aerobic respiration has two stages.
• Where do they occur? mitochondria
• What are the three end products of this process?
  Oxygen, water, and ENERGY
• Stage 2 is called citric acid cycle.
• Stage 3 is called electron transport chain.

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Figure 4.5 pg 77
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Cellular Respiration
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Respiration

• C6H12O6 6O2 ? 6CO2 6H2O ENERGY

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4.5 Metabolic Pathways

• Metabolic pathways are a sequence of
  enzyme-controlled reactions.
• lipids protein pathways these two nutrients
  can be used to make ATP. Where they plug into
  the process is going to depend on how many
  Carbons are in the piece the cell is working on.
  How many ATPs formed will also depend on this.

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Genetic Info

• Genetic information must tell cells how to
  position amino acids correctly in polypeptide
  chains.
• The function of DNA is to direct the activities
  of the cell and to direct the synthesis of
  protein by the cell.
• DNA molecules are replicated during what phase of
  the cell cycle? Interphase

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4.6 Nucleic Acids (DNA RNA)

• Deoxyribonucleic acid (DNA) contains the genetic
  code needed for the synthesis of each protein
  (including enzymes) required by the cell.
• The "backbone" of DNA is composed of alternating
  nucleotides joined so that phosphate and sugar
  portions alternate. The sugar is named
  deoxyribose.
• Name the four bases. Adenine, Thymine, Cytosine,
  Guanine
• What are the two base complementary pairs of DNA?
  A-T C-G
• DNA is double strands and twists to form a double
  helix.
• The sequence of nucleotides in a DNA molecule
  gives the sequence of amino acids for a given
  protein.

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DNA
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4.7 RNA

• What is the sugar in RNA called? ribose
• Name the four bases Adenine, Cytosine, Guanine,
  Uracil.
• RNA is single-stranded.
• There are 3 types of RNA.
• Ribosomal RNA (rRNA)- make ribosomes.
• Messenger RNA (mRNA) copy and transfer the
  genetic information to the cytoplasm where
  proteins are manufactured.
• Transfer RNA (tRNA) position amino acids along a
  stand of mRNA. tRNA join and form a protein
  molecule.

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RNA
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4.7 Protein Synthesis

• Transcription is the transferring of info from
  the DNA in the nucleus to the mRNA.
• Translation is the converting from the language
  of nucleic acids to the language of amino acids
  this occurs in the cytoplasm.
• Transcription DNA ? RNA
• Translation RNA ? protein

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4.7 Protein Synthesis

• mRNA molecules copy part of the DNA code in the
  nucleus.
• They then travel to the ribosome where protein
  synthesis will occur.
• They lie across the ribosome and wait for the
  tRNA to bring in the appropriate amino acids.
• The correct amino acids will be lined up because
  the tRNA bases are arranged in anticodon that are
  complementary to the codons of the bases of the
  mRNA.
• The amino acids bond with peptide bonds to each
  other to form a protein.

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RNA Transcription
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4.8 DNA Replication

• Each new cell must be provided with an exact
  replica of the parent cell's DNA. When does DNA
  replication occur? Mitosis
• The DNA molecule splits. Nucleotides form
  complementary pairs with the original strands.
• Each new DNA molecule consists of one parental
  strand and one newly synthesized strand of DNA.
• What is a mutation? Changes in DNA can be
  harmful, helpful, or have no effect.
• The occurrence of mutations may be spontaneous or
  a result of exposure to ionizing radiation and
  toxic chemicals
• DNA of the parent cell must be replicated
  accurately so that the new cell can maintain life
  functions, build cell parts and metabolize
  nutrients.

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DNA Replication
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Work Cited

• DNA Replication image. http//www.genelex.com/pate
  rnitytesting/paternityslide1.html
• DNA image. http//www.tokyo-med.ac.jp/genet/picts/
  dnaL.jpg
• DNA, gene, chromosome image. http//www.alzheimers
  .org/unraveling/09.htm
• RNA image. http//library.thinkquest.org/C0123260/
  basic20knowledge/images/basic20knowledge/RNA/str
  ucture20of20RNA.jpg
• RNA transcription image. http//www.accessexcellen
  ce.org/AE/AEPC/NIH/gene03.html
• Cellular respiration image. http//faculty.clinton
  cc.suny.edu/faculty/Michael.Gregory/files/Bio2010
  1/Bio2010120Lectures/Cellular20Respiration/cell
  ul13.gif