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Factors Affecting Rates of Respiration

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Factors Affecting Rates of Respiration Temperature- For every 10 degree C rise in temperature between 0-35 C the rate of respiration increases 2X 4X. – PowerPoint PPT presentation

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Title: Factors Affecting Rates of Respiration


1
Factors Affecting Rates of Respiration
  • Temperature- For every 10 degree C rise in
    temperature between 0-35 C the rate of
    respiration increases 2X 4X.
  • Storage temperature for harvested plant parts is
    often critical because these parts continue to
    respire after harvest ( a catabolic process)
    which causes a build up of heat, and the
    breakdown of the product.

2
Factors Affecting Rates of Respiration
  • Most plants grow better when night time
    temperatures are 5 degrees C lower than day time
    temperatures.
  • This is because lower night time respiration
    reduces the use of carbohydrates and allows more
    carbohydrates to be stored or used for growth.

3
Factors Affecting Rates of Respiration
  • Oxygen concentration- Generally speaking, lower
    oxygen level results in the reduction of
    respiration.
  • Controlled atmosphere (CA) storage in which
    oxygen is decreased is useful in storage of
    fruits and vegetables because of lower
    respiration rates.

4
Factors Affecting Rates of Respiration
  • Soil conditions- Compacted and/or wet soil
    conditions result in low oxygen in the root zone
    and reduced root respiration.
  • Consequently, roots dont function well in
    supplying mineral nutrients essential for the
    activity of respiratory enzymes which decreases
    overall respiration.

5
Factors Affecting Rates of Respiration
  • Light- Lower light intensities result in lower
    respiration rates.
  • Lower photosynthesis rates in low light supply
    fewer carbohydrates essential for respiration.
  • Plant growth- As a plant grows it depends on
    energy to be supplied by respiration.
  • The more growth that is occurring, the higher the
    respiration rate must be.

6
Summary of Respiration
  • Aerobic Respiration
  • Glycolysis
  • Transition Rx.
  • Krebs Cycle
  • Electron Transport Chain
  • Anaerobic Respiration
  • Pyruvate ?
  • Lactic Acid
  • Mixed Acids
  • Alcohol CO2
  • Recycle NADH
  • 2 ATP / Glucose

7
  • Amino Acid Catabolism

8
Amino Acids
  • Building blocks for polymers called proteins
  • Contain an amino group, NH2, and a carboxylic
    acid, COOH
  • Can form zwitterions have both positively
    charged and negatively charged groups on same
    molecule
  • 20 required for humans

9
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10
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11
Peptide Bond
  • Connect amino acids from carboxylic acid to amino
    group
  • Produce amide linkage -CONH-
  • Holds all proteins together
  • Indicate proteins by 3-letter abbreviation

12
Sequence of Amino Acids
  • Amino acids need to be in correct order for
    protein to function correctly
  • Similar to forming sentences out of words

13
Transaminase enzymes (aminotransferases)
  • Catalyze the reversible transfer of an amino
    group between two a-keto acids.

14
Example of a Transaminase reaction
  • Aspartate donates its amino group, becoming the
    a-keto acid oxaloacetate.
  • a-Ketoglutarate accepts the amino group, becoming
    the amino acid glutamate.

15
  • In another example, alanine becomes pyruvate as
    the amino group is transferred to
    a-ketoglutarate.

16
  • Essential amino acids must be consumed in the
    diet.
  • Mammalian cells lack enzymes to synthesize their
    carbon skeletons (a-keto acids). These include
  • Isoleucine, leucine, valine
  • Lysine
  • Threonine
  • Tryptophan
  • Phenylalanine (Tyr can be made from Phe.)
  • Methionine (Cys can be made from Met.)
  • Histidine (Essential for infants.)

17
Amino Acid Metabolism
  • Metabolism of the 20 common amino acids is
    considered from the origins and fates of their
    (1) Nitrogen atoms (2) Carbon skeletons
  • For mammals Essential amino acids must be
    obtained from dietNonessential amino acids - can
    be synthesized

18
The Nitrogen Cycle and Nitrogen Fixation
  • Nitrogen is needed for amino acids, nucleotides
  • Atmospheric N2 is the ultimate source of
    biological nitrogen
  • Nitrogen fixation a few bacteria possess
    nitrogenase which can reduce N2 to ammonia
  • Nitrogen is recycled in nature through the
    nitrogen cycle

19
Fig 17.1 The Nitrogen cycle
20
Nitrogenase
21
Assimilation of Ammonia
  • Ammonia generated from N2 is assimilated into low
    molecular weight metabolites such as glutamate or
    glutamine
  • At pH 7 ammonium ion predominates (NH4)
  • At enzyme reactive centers unprotonated NH3 is
    the nucleophilic reactive species

22
A. Ammonia Is Incorporated into Glutamate
  • Reductive amination of a-ketoglutarate by
    glutamate dehydrogenase occurs in plants, animals
    and microorganisms

23
Glutamine Is a Nitrogen Carrier in Many
Biosynthetic Reactions
  • A second important route in assimilation of
    ammonia is via glutamine synthetase

24
Glutamate synthase transfers a nitrogen to
a-ketoglutarate
Prokaryotes plants
25
Alternate amino acid production in prokaryotes
Especially used if NH3 is low. Km of Gln
synthetase lower than Km of Glu dehydrogenase.
26
The First Step in Amino Acid Degradation is the
Removal of Nitrogen
  • Amino acids released from protein turnover can be
    resynthesized into proteins.
  • Excess amino acids are degraded into specific
    compounds that can be used in other
  • metabolic pathways.
  • This process begins with the removal of the amino
    group, which can be converted to
  • urea and excreted.
  • The ?-ketoids that remain are metabolized so that
    their carbon skeletons can enter
  • glycolysis, gluconeogenesis, or the TCA cycle.

27
The Biosynthesis of Amino Acids
  • Amino acids are the building blocks of proteins
    and the nitrogen source of many
  • other important molecules including nucleotides,
    neurotransmitters, and prosthetic
  • groups such as porphyrins.
  • Ammonia is the source of all nitrogen for all of
    the amino acids.
  • The carbon backbones come from the glycolytic
    pathway, the pentose phosphate
  • pathway, and/or the TCA cycle.
  • Amino acid biosynthesis is feedback regulated to
    ensure that all amino acids are
  • maintained in sufficient amounts for protein
    synthesis and other processes.

28
Summary of Protein and Amino Acid Degradation
  • Proteins are degraded to amino acids.
  • Protein turnover is tightly regulated.
  • The first step in amino acid degradation is the
    removal of nitrogen.
  • Ammonium ion is converted into urea in most
    terrestrial vertebrates.
  • Carbon atoms of degraded amino acids emerge as
    major metabolic intermediates.
  • Inborn errors of metabolism can disrupt amino
    acid degradation.

29
Summary of Amino Acid Biosynthesis
  • Microorganisms use ATP and a powerful reductant
    to reduce
  • atmospheric nitrogen to ammonia.
  • Amino acids are made from intermediates of the
    TCA cycle
  • and other major pathways.
  • Amino acid metabolism is regulated by feedback
    inhibition.
  • Amino acids are precursors of many molecules.

30
Overview of Nucleotide Biosynthesis
  • Nucleotides serve as active precursors of nucleic
    acids.
  • ATP is the universal currency of energy.
  • Nucleotide derivatives such as UDP-glucose
    participate in
  • bioynthetic processes.
  • Nucleotides are essential components of signal
    transduction
  • pathways.

31
Two Classes of Pathways for the Synthesis of
Nucleotides.
  • In the salvage pathway, a base is attached
  • to a ribose, activated in the form of 5-
  • phosphoribosyl-1-pyrophosphate (PRPP).
  • In de novo synthesis, the base itself is
  • synthesized from simpler starting materials,
  • including amino acids.
  • ATP hydrolysis is necessary for de novo
  • synthesis.

32
Summary of Nucleotide Biosynthesis
  • In de novo synthesis, the pyrimidine ring is
    assembled from
  • bicarbonate, aspartate, and glutamine.
  • Purine bases can be synthesized de novo or
    recycled by salvage
  • pathways.
  • Deoxyribonucleotides are synthesized by the
    reduction of
  • ribonucleotides.
  • Key steps in nucleotide biosynthesis are feeback
    regulated.
  • NAD, FAD, and Coenzyme A are formed from ATP.
  • Disruptions in nucleotide metabolism can cause
    pathological conditions.

33
Proteins
34
Structure of Proteins
  • Four organizational levels
  • Primary structure amino acid sequence
  • Secondary structure arrangement of chains around
    an axis
  • Pleated sheet
  • Alpha helix right-handed helix

35
Pleated Sheets
36
Alpha Helix
37
Tertiary Structure
  • Spatial relationships of amino acids relatively
    far apart in protein chain
  • Globular proteins compact spherical shape

38
Quaternary Structure
  • Structure when two or more amino acid sequences
    are brought together
  • Hemoglobin has four units arranged in a specific
    pattern

39
Intermolecular Forces in Proteins
  • Hydrogen bonding
  • Ionic bonds
  • Disulfide linkages
  • Dispersion forces

40
Protein metabolism
Transamination use the essential AA to
synthesize the others!
41
Protein metabolism
Another route Intestinal bacteria -gt ammonia
(toxic) -gt liver uses it to make amino acids
42
Protein metabolism
Amino acids C, H, O plus amine group with N
43
Protein metabolism
Amino acids are broken down into a) ammonia -gt
urea b) pyruvate or molecules that are part of
the krebs cycle -gt respired for energy, or
converted to fats or glucose
44
  • Proteins are degraded into amino acids.
  • Protein turnover is tightly regulated.
  • First step in protein degradation is the removal
    of the nitrogen
  • Ammonium ion is converted to urea in most
    mammals.
  • Carbon atoms are converted to other major
    metabolic intermediates.
  • Inborn errors in metabolism

45
  • Amino acids used for synthesizing proteins are
    obtained by degrading other proteins
  • Proteins destined for degradation are labeled
    with ubiquitin.
  • Polyubiquinated proteins are degraded by
    proteosomes.
  • Amino acids are also a source of nitrogen for
    other biomolecules.

46
  • Excess amino acids cannot be stored.
  • Surplus amino acids are used for fuel.
  • Carbon skeleton is converted to
  • AcetylCoA
  • AcetoacetylCoA
  • Pyruvate
  • Citric acid cycle intermediate
  • The amino group nitrogen is converted to urea and
    excreted.
  • Glucose, fatty acids and ketone bodies can be
    formed from amino acids.

47
1. Protein Degradation
  • proteins are a vital source of amino acids.
  • Discarded cellular proteins are another source of
    amino acids.

48
Biotechnology
49
What Is Biotechnology?
  • Using scientific methods with organisms to
    produce new products or new forms of organisms
  • Any technique that uses living organisms or
    substances from those organisms to make or modify
    a product, to improve plants or animals, or to
    develop microorganisms for specific uses

50
What Is Biotechnology?
  • GMO- genetically modified organisms.
  • GEO- genetically enhanced organisms.
  • With both, the natural genetic material of the
    organism has been altered.
  • Roots in bread making, wine brewing, cheese and
    yogurt fermentation, and classical plant and
    animal breeding

51
What Is Biotechnology?
  • Manipulation of genes is called genetic
    engineering or recombinant DNA technology
  • Genetic engineering involves taking one or more
    genes from a location in one organism and either
  • Transferring them to another organism
  • Putting them back into the original organism in
    different combinations

52
What is the career outlook in biotechnology?
  • Biotech in 1998
  • 1,300 companies in the US
  • 2/3 have less than 135 employees
  • 140,000 jobs
  • Jobs will continue to increase exponentially
  • Jobs are available to high school graduates
    through PhDs

53
What Subjects Are Involved With Biotechnology?
  • Multidisciplinary- involving a number of
    disciplines that are coordinated for a desired
    outcome
  • Science
  • Life sciences
  • Physical sciences
  • Social sciences

54
What Subjects Are Involved With Biotechnology?
  • Mathematics
  • Applied sciences
  • Computer applications
  • Engineering
  • Agriculture

55
What Are the Stages of Biotechnology Development
  • Ancient biotechnology- early history as related
    to food and shelter Includes domestication
  • Classical biotechnology- built on ancient
    biotechnology Fermentation promoted food
    production, and medicine
  • Modern biotechnology- manipulates genetic
    information in organism Genetic engineering

56
What Are the Areas of Biotechnology?
  • Organismic biotechnology- uses intact organisms
    Does not alter genetic material
  • Molecular biotechnology- alters genetic makeup to
    achieve specific goals
  • Transgenic organism- an organism with
    artificially altered genetic material

57
What Are the Benefits of Biotechnology?
  • Medicine
  • Human
  • Veterinary
  • Biopharming
  • Environment
  • Agriculture
  • Food products
  • Industry and manufacturing

58
What Is Molecular Biology?
  • Molecular biology- study of molecules in cells
  • Metabolism- processes by which organisms use
    nutrients
  • Anabolism- building tissues from smaller
    materials
  • Catabolism- breaking down materials into smaller
    components

59
What Is a Cell?
  • Cell- a discrete unit of life
  • Unicellular organism- organism of one cell
  • Multicellular organism- organism of many cells
  • Prokaryote- cells that lack specific nucleus
  • Eukaryote- cells with well-defined nucleus

60
What Is a Cell?
  • Cells are building blocks
  • Tissue- collection of cells with specific
    functions
  • Organs- collections of tissues with specific
    functions
  • Organ systems- collections of organs with
    specific functions

61
What Are the Structures in Molecular Genetics?
  • Molecular genetics- study of genes and how they
    are expressed
  • Chromosome- part of cell nucleus that contains
    heredity information and promotes protein
    synthesis
  • Gene- basic unit of heredity on a chromosome
  • DNA- molecule in a chromosome that codes genetic
    information

62
Deoxyribonucleic Acid (DNA)
63
What Is Ribonucleic Acid (RNA)?
  • Transcription- process of RNA production by DNA
  • DNA-thread-like molecule which decodes DNA
    information

64
What Is Ribonucleic Acid (RNA)?
  • Kinds of RNA
  • mRNA- RNA molecules that carry information that
    specifies amino acid sequence of a protein
    molecule during translation
  • rRNA- RNA molecules that form the ribosomal
    subunits Mediate the translation of mRNA into
    proteins
  • tRNA- molecules that decode sequence information
    in and mRNA
  • snRNA- very short RNA that interconnects with to
    promote formation of mRNA

65
What Are Genetic Engineering Organisms?
  • Genetic engineering- artificially changing the
    genetic information in the cells of organisms
  • Transgenic- an organism that has been genetically
    modified
  • GMO- a genetically modified organism
  • GEO- a genetically enhanced organism

66
How Can Genetically Engineered Plants Be Used?
  • Agriculture
  • Horticulture
  • Forestry
  • Environment
  • Food Quality

67
How Do We Create Transgenic Organisms?
  • Donor cell- cell that provides DNA
  • Recipient cell- cell that receives DNA
  • Protocol- procedure for a scientific process
  • Three methods used in gene transfer
  • Agrobacterium gene transfer- plasmid
  • Ballistic gene transfer- gene gun
  • Direct gene transfer- enzymes

68
How Does Agrobacterium Gene Transfer Work?
  1. Extract DNA from donor
  2. Cut DNA into fragments
  3. Sort DNA fragments
  4. Recombine DNA fragments
  5. Transfer plasmids with bonded DNA
  6. Grow transformed (recipient) cells

69
What Are Methods of Classical Biotechnology?
  • Plant breeding- improvement of plants by breeding
    selected individuals to achieve desired goals
  • Cultivar- a cultivated crop variety

70
What Are Methods of Classical Biotechnology?
  • Plant breeding methods
  • Line breeding- breeding successive generations of
    plants among themselves
  • Crossbreeding- breeding plants of different
    varieties or species
  • Hybridization- breeding individuals from two
    distinctly different varieties
  • Selection

71
Why Are Plants Genetically Engineered?
  • Resist pests
  • Resist herbicides
  • Improved product quality
  • Pharmaceuticals
  • Industrial products

72
These definitions imply biotechnology is needed
because
  • Nature has a rich source of variation

But we know nature does not have all of the
traits we need
73
What controls this natural variation?
Allelic differences at genes control a specific
trait
Definitions are needed for this statement
74
What is the difference between genes and alleles
for Mendels Traits?
Mendels Genes Plant height
Seed shape
Smooth Wrinkled Allele
Tall Short Allele
75
Central Dogma of Molecular Genetics
(The guiding principle that controls trait
expression)
76
In General, Plant Biotechnology Techniques Fall
Into Two Classes
77
Gene Manipulation Starts At the DNA Level
Source Access Excellence
78
DNA Is Packaged
is condensed into
Source Access Excellence
79
PCR Animation
Denaturation DNA melts Annealing Primers
bind Extension DNA is replicated
80
Complementary Genetics (cont.)
4. Gene fragment used to screen library
81
Map-based Cloning
82
Gene Manipulation
  • It is now routine to isolate genes
  • But the target gene must be carefully chosen
  • Target gene is chosen based on desired phenotype

Function
Glyphosate (RoundUp) resistance EPSP
synthase enzyme
Increased Vitamin A content Vitamin A
biosynthetic pathway enzymes
83
The RoundUp Ready Story
  • Glyphosate is a broad-spectrum herbicide
  • Active ingredient in RoundUp herbicide
  • Kills all plants it come in contact with
  • Inhibits a key enzyme (EPSP synthase) in an
    amino acid pathway
  • Plants die because they lack the key amino acids
  • A resistant EPSP synthase gene allows crops
  • to survive spraying

84
RoundUp Sensitive Plants
Glyphosate
X
X
Without amino acids, plant dies
X
X
85
RoundUp Resistant Plants
Shikimic acid Phosphoenol pyruvate
Glyphosate
RoundUp has no effect enzyme is resistant to
herbicide
Bacterial EPSP synthase
3-enolpyruvyl shikimic acid-5-phosphate (EPSP)
With amino acids, plant lives
Aromatic amino acids
86
The Golden Rice Story
  • Vitamin A deficiency is a major health problem
  • Causes blindness
  • Influences severity of diarrhea, measles
  • gt100 million children suffer from the problem
  • For many countries, the infrastructure doesnt
    exist
  • to deliver vitamin pills
  • Improved vitamin A content in widely consumed
    crops
  • an attractive alternative

87
?-Carotene Pathway in Plants
88
The Golden Rice Solution
?-Carotene Pathway Genes Added
Daffodil gene
Single bacterial gene performs both functions
Daffodil gene
89
Metabolic Pathways are Complex and Interrelated
Understanding pathways is critical to
developing new products
90
Modifying Pathway Components Can Produce New
Products
Turn On Vitamin Genes Relieve Deficiency
Modified Lipids New Industrial Oils
Increase amino acids Improved Nutrition
91
Trait/Gene Examples
Gene
Trait
RoundUp Ready
Bacterial EPSP
Golden Rice
Complete Pathway
Plant Virus Resistance
Viral Coat Protein
Male Sterility
Barnase
Plant Bacterial Resistance
p35
Salt tolerance
AtNHX1
92
Introducing the Gene or Developing Transgenics
Steps
1. Create transformation cassette
2. Introduce and select for transformants
93
Transformation Cassettes
Contains
94
Gene of Interest
95
Selectable Marker
96
Effect of Selectable Marker
Non-transgenic Lacks Kan or Bar Gene
X
Transgenic Has Kan or Bar Gene
97
Insertion Sequences
98
Lets Build A Complex Cassette
pB19hpc (Golden Rice Cassette)
99
Delivering the Gene to the Plant
  • Transformation cassettes are developed in the lab
  • They are then introduced into a plant
  • Two major delivery methods

100
Plant Tissue Culture A Requirement for Transgenic
Development
Callus grows
A plant part Is cultured
Shoots develop
Shoots are rooted plant grows to maturity
101
But Natures Agrobacterium Has Problems
Infected tissues cannot be regenerated (via
tissue culture) into new plants
Why?
  • Phytohormone balance incorrect regeneration

Transferred DNA (T-DNA) modified by
Solution?
  • Removing phytohormone genes
  • Retaining essential transfer sequences
  • Adding cloning site for gene of interest

102
The Gene Gun
  • DNA vector is coated onto gold or tungsten
    particles
  • Particles are accelerated at high speeds by the
    gun
  • Particles enter plant tissue
  • DNA enters the nucleus and
  • incorporates into chromosome
  • Integration process unknown

103
Transformation Steps
Prepare tissue for transformation
Introduce DNA
  • Agrobacterium or gene gun

Culture plant tissue
Field test the plants
  • Multiple sites, multiple years

104
The Lab Steps
105
Lab Testing The Transgenics
Transgene Bt-toxin protein
Transgene CBF transcription factors
106
What is plant biotechnology?
107
Benefits of biotechnology
108
What Is Cloning?
  • Clone- new organism that has been produced
    asexually from a single parent
  • Genotype is identical to parent
  • Cells or tissues are cultured

109
What Is Bioremediation?
  • Bioremediation- using biological processes to
    solve environmental problems
  • Biodegradation- natural processes of microbes in
    breaking down hydrocarbon materials
  • Biodegradable- capable of being decomposed by
    microbes

110
How Can Bioremediation Be Used?
  • Oil spills
  • Wastewater treatment
  • Heavy metal removal
  • Chemical degradation

111
What Is Phytoremediation?
  • Phytoremediation- process of plants being used to
    solve pollution problems
  • Plants absorb and break down pollutants
  • Used with heavy metals, pesticides, explosives,
    and leachate

112
References
  • http//www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/
    part1/22-aanit.ppt
  • http//www.chem.uwec.edu/Chem454/amino1.ppt
  • http//ps2009.stainedscrubs.com/genfiles/0120SB2
    0Courseworks/Biochem_WS_IV.ppt
  • http//science.kennesaw.edu/jpowers/aminoacid1.pp
    t
  • http//academics.vmi.edu/biochem/Chapter_17.ppt
  • http//newark.rutgers.edu/jimms/P13.ppt

113
Referance
  • http//sunny.crk.umn.edu/courses/PIM/1030/Chapter
    207-20Photosynthesis,Respiration,and..ppt
  • http//sunny.crk.umn.edu/courses/PIM/1030/Chapter
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  • http//www.geneontology.org/minutes/20040822_Stanf
    ord_Content/metabolism_post-meeting.ppt

114
references
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    pt
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    ,1,MICROBIAL METABOLISM
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115
References
  • http//www.newman.edu.hk/ecampus/wk/bioweb/ALBio/A
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  • http//www.coe.unt.edu/ubms/documents/classnotes/S
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116
References
  • http//docushare.harford.edu/dsweb/Get/Document-15
    6422/Cell20Lab.ppt
  • http//www.biosci.ohio-state.edu/pcmb/osu_pcmb/cou
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117
References
  • http//iaffa.bizland.com/sitebuildercontent/sitebu
    ilderfiles/biotechintro.ppt
  • http//www.ag.ndsu.nodak.edu/biotech/presentations
    /techniques-of-biotechnology-mcclean-good.ppt
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