BIOC 3300 Lecture Notes - Lecture 22: Cystathionine, Methionine Synthase, Essential Amino Acid

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coffeeoyster95

4 Apr 2016

School

Dalhousie University

Department

Biochem & Molecular Biology

Course

BIOC 3300

Professor

Mc Leod Roger

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Paps (phosphoadenosine 5"- phosphosulfate: what is the key intermediate in the reduction of inorganic sulfur, describe the inorganic sulfur reduction reaction, describe the synthesis of cysteine in plants and bacteria. Serine is activated with an acetate from acetyl-coa. So is combined with an atp: why is an acetate added to serine in the synthesis of cysteine, describe the synthesis of. *cystathionine* in plants and bacteria. (going back up the cycle) to form adenosine 5"- phospho*sulfate* (aps) Another pi (from a second atp) is then added to 3" position of. Nadph*), requiring fad, fmn, and cofactor with fe-s center. *methionine* + *serine* (making glutathionine) and then glutathionine is cleaved to make cysteine if there is low [met] (which is an essential amino acid), cannot synthesize cysteine (because met is a source of sulfur) In mammals, where is the cysteine sulfur supplied from: in mammals, where is the carbon skeleton for cysteine supplied from, what is the total atp,

Related Questions

Microbiology Unit 2 Applied and Environmental Assignment Part 1: Identify Nutritional requirements from Chapter 6&14 (and review from chapters 1 & 2) 1. Determine which of the 4 macromolecules require the following elements: a. Carbon: carbohydrates___ lipids___ proteins___ nucleic acids___ b. Nitrogen: carbohydrates___ lipids___ proteins___ nucleic acids___ c. Sulfur: carbohydrates___ lipids___ proteins___ nucleic acids___ 2. The essential elements mentioned above are cycled through cells and the earth in biogeochemical cycles (the carbon, nitrogen, and sulfur cycles.)Select the correct answer or fill in the blanks to summarize these cycles: a. Carbon dioxide is taken in from the atmosphere by [autotrophs/heterotrophs] and converted to glucose through carbon ________________. When heterotrophs eat autotrophs they use catabolism to break down glucose to make ATP and waste carbon is released as ___________. b. There is plenty of nitrogen available in the atmosphere but it is not accessible to organisms because it is in the form of Nitrogen gas (N2). N2 is fixed by [bacteria/plants/animals] and converted to ammonia (NH3.) NH3 can be used by [bacteria/plants/animals] to build their cells. Next, by consuming food with amino acids,[bacteria/plants/animals] can get access to nitrogen for their own cellular needs. c. There is also a good quantity of sulfur in dirt, rocks, and the atmosphere. Sulfur cycles between H2S => S0 => SO4 => SH groups in Proteins => back to H2S.Using _________________ respiration, anoxygenic photosynthesis, and chemolithoautotrophy [bacteria/plants/animals]convert H2S and S0 to SO4 which is taken in by [bacteria/plants/animals] and used to build their cells. When [bacteria/plants/animals]eat plants they take in essential amino acids containing sulfur and recycle these to make their proteins. d. _________________ break down waste and dead organisms and recycle nutrients back into the cycles. *The C and N are summarized here: https://youtu.be/2D7hZpIYlCA and https://youtu.be/leHy-Y_8nRs 3. Match the main metabolic classifications to the description: Classifications: photoautotroph/ photoheterotroph/ chemoautotroph/ chemoheterotroph o A microbe that makes its own food by taking carbon from CO2 in the atmosphere and its energy from sunlight o A microbe that makes its own food by taking carbon from CO2 in the atmosphere and its energy from reduced inorganic chemicals o A microbe that eats other organisms to get organic carbon and energy o A microbe that eats other organisms to get organic carbon but gets energy from sunlight 4. Identify the phases of the bacterial growth curve and define what occurs in each phase Phase A = ______________ Definition: Phase B = ______________ Definition: Phase C = ______________ Definition: Phase D = ______________ Definition: Part 2: Unique ecosystems containing microbes 5. Watch the video that shows hydrothermal vents: https://youtu.be/RO3nO98gH_M a. Describe bacteria that live at the vents using terms from the unit 2 reading guide: ________________________________________________________________________ b. Write a 2-3 sentence reflection about hydrothermal vents and the contribution of microbes to this ecosystem: 6. Apply what you have learned to the TED-Ed video about Biofilms: https://youtu.be/pHLP5CZMnL4 a. Give the terms for cell structures mentioned in the video that we learned in Chapter 4 and 7: i. âsticky appendagesâ thatallows bacteria to attach and begin the biofilm: _______________ ii. Extracellular matrix/gooey matrix that holds cells together: ____________________________ iii. Exchange genetic information while packed together: ____________________________ iv. Communicate with each other by _________________________________________ sensing. v. Produce chemical to kill microbial competitors: ____________________________ factor.

An extraterrestrial organism (ET) is discovered whose basic cellbiology seems pretty much the same as that of
terrestrial organisms except that it uses a different genetic codeto translate RNA into protein. You set out to break the
code by translation experiments using RNAs of known sequence andcell-free extracts of ET cells to supply the necessary
protein-synthesizing machinery. In experiments using the RNAsbelow, the following results were obtained when the 20
possible amino acids were added either singly or in differentcombinations of two or three:
RNA 1: 5?-GCGCGCGCGCGCGCGCGCGCGCGCGCGC-3?
RNA 2: 5?-GCCGCCGCCGCCGCCGCCGCCGCCGCCGCC-3?
Using RNA 1, a polypeptide was produced only if alanine and valinewere added to the reaction mixture. Using RNA 2, a polypeptide wasproduced only if leucine and serine and cysteine were added to thereaction mixture. Assuming that protein synthesis can startanywhere on the template, that the ET genetic code isnonoverlapping and linear, and that each codon is the same length(like the terrestrial triplet code), how many nucleotides does anET codon contain?
(a)2 (b)3 (c)4 (d)5 (e)6

Messenger RNA (mRNA)...

a) Is a structural part of a ribosome

b) Brings amino acids to DNA

c) Carries genetic information from the nucleus to the cytoplasm

d) Is a structural part of a chromosome

e) Initiates and directs chemical reactions

Mr. Potato is homozygous dominant (KK), his son, Potato Jr. is heterozygous (Kk). Based on this information, what are the possible genotypes for Mrs. Potato? (Hint: use a Punnet Square).

a) Her genotype is definitely kk

b) Her genotype is either Kk or kk

c) Her genotype is either KK or Kk

d) Her genotype is either KK, or Kk, or kk

e) Mr. Potato cannot be Potato Jrâs biological father

12. Homologous chromosomes:

a) Are members of different chromosome pairs

b) Are genetically identical

c) Carry genetic information that influences the same traits (same genes but probably different alleles)

d) Are only inherited from the mother

e) Are only inherited from the father.

âFitnessâ in an evolutionary sense, refers to an individualâs:

a) Strength

b) Reproductive success

c) Aggressiveness

d) Size

e) Age at death

The fact that individuals who possess favorable traits are more likely to survive and reproduce than those who possess less favorable traits is the basis for the theory of...

a) uniformitarianism.

b) natural selection.

c) the inheritance of acquired characteristics.

d) catastrophism.

e) the fixity of species.

Even with strong selection, genetic variation of a population can be maintained because:

a) Selection only affects one gene at a time.

b) The effects of many alleles are hidden from selection by the effects of other alleles

c) Mutation constantly adds new alleles at an extremely fast rate.

d) Populations always go extinct before their gene frequencies are dramatically altered.

e) Only a and c

Gene Flow is defined as the:
a) Production of new alleles
b) New musical group in which Adam Levine will be the leading vocalist
c) Exchange of genes between populations
d) differential reproductive success of individuals
e) Process by which a DNA base gets extracted out of the nucleus to initiate the process of protein synthesis.

The basic unit of DNA is a molecule called a: a) Nucleotide

b) Base
c) Thymine
d) Prokaryoticcell e) mRNA

How many bases code for one amino acid? a) one

b) two
c) it depends on what amino acid it is d) three
e) four

Hemophilia is a condition that affects: a) more females than males
b) more males than females
c) females and males equally

d) only children born prematurely
e) individuals with a missing portion of chromosome number 5

A clear example of directional selection is:
a) Darwin finches with deeper and thicker beaks associated to a severe drought b) Sickle cell anemia in regions in which Malaria is endemic
c) Achondroplasticdwarfism
d) Fly halteres becoming fully developed wings after modification of a hox gene e) all of the above

Meiosis is evolutionarily significant because:
a) New combination of alleles can arise through independent assortment and crossing over

22.

23.

24.

25.

26.

b) It is the mechanism by which body tissues are repaired
c) It creates somatic cells that are crucial for our body organs to maintain us alive d) It allows forensics to determine the cause of death of unidentified people
e) none of the above

Homologous chromosomes:

a) Are exact copies of each other and contain exactly the same genetic material
b) Are members of different chromosome pairs
c) Are only inherited from the father
d) carry genetic information that influences the same traits (the same genes), however, each of the homologous chromosomes can contain different versions of the same gene (different alleles).

e) carry genetic information that influences different traits because each of the homologous chromosomes contains completely different genes at very different loci

How many chromosome pairs occur in a normal human somatic cell?

a) 46 b) 23 c) 22 d) 24 e) 45

What is the scientific method? Use bullet points to describe the 4 major components.

How is a hypothesis different from a theory?

List the four major components (described during class) necessary for natural selection to occur [AKA Darwinâs Four Postulates] (PDF1-3).

27. Who was Thomas Malthus? In what way(s) Malthus was influential for Darwinâs Theory of Natural Selection? Hint: populations vs resources.

29. What amino acids are being coded for by the gene segment provided below? Nucleotide triplets and their corresponding amino acids are:
ACA= Cysteine; AAA=Phenylalanine; TGG=Threonine; CCT=Glycine; GAT=Leucine; ATA=Tyrosine; AGG=Serine; TCT=Arginine

a) Threonine, serine, glycine, tyrosine, leucine, phenylalanine, arginine, cysteine.

b) Tyrosine, leucine, glycine, threonine, arginine, threonine, serine, cysteine.

c) Arginine, cysteine, serine, glycine, threonine, leucine, phenylalanine, tyrosine.

d) Phenylalanine, leucine, tyrosine, glycine, serine, threonine, cysteine, arginine.

e) Phenylalanine, leucine, tyrosine, glycine, threonine, phenylalanine, arginine, serine.

BIOC 3300 Lecture Notes - Lecture 22: Cystathionine, Methionine Synthase, Essential Amino Acid

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