GENBIO2 long quiz

• The central dogma in molecular biology

  -        the flow of genetic information: DNA-transcription-RNA-translation-PROTEIN

   
• The DNA

  -        1950’s

  -        Rosalind Franklin – X-ray photo of DNA

  -        Watson and Crick – describes DNA molecule from franklin’s X-ray.
• What is DNA?

  -        Deoxyribonucleic Acid, made up of nucleotides(DNA molecules) in a DNA double helix.
•        Nucleotide:

  -        Phosphate group

  -        5-carbon sugar

  -        Nitrogenous base

  -        2nm wide
• Chargaff’s rule

  Ø  Adenine with Thymine

  Ø  Guanine with Cytosine

  Ø  Their amounts in a given DNA molecule will be about the same.
• Replication

  -        Is semi conservative

  -        Each newly synthesized molecule contains 1 “parent template” strand and 1 new “daughter strand”
• Transcription (RNA synthesis)

  -        RNA is an important type of nucleic acid that plays several roles in the production of protein
• Two types of nucleic acids

  DNA

  ·        Double-stranded

  ·        Deoxyribose as sugar

  ·        Thymine

  ·        Cytosine

  ·        Adenine

  ·        Thymine

  RNA

  ·        Single-stranded

  ·        Ribose as sugar

  ·        Uracil

  ·        Cytosine

  ·        Adenine

  ·        Guanine
• Transcription

  -        The mechanism by which a template strand of DNA is utilized by specific RNA polymerases to generate one of the 4 different types of RNA.
• Types of RNA

  1.mRNA(messenger RNA)

  2.tRNA(transfer RNA)

  3.rRNA(ribosomal RNA)

  4.snRNA(small nuclear RNA)
• Messenger RNA – encodes amino acid sequence of a polypeptide, polypeptide is the building blocks of proteins. Carries the actual code that specifies the amino acid sequence in polypeptide.
• Transfer RNA – brings amino acids to the ribosomes during translation.
• Ribosomal RNA – with ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA.
• Small nuclear RNA – with proteins, forms complexes that are used in RNA processing in eukaryotes.
• Complete transcription of an RNA molecule

  -        Transcription begins at the promoter, proceeds trough the coding region, and ends at the terminator.
• Codon – a triplet of adjacent nucleotides in the messenger RNA chain that codes for a specific amino acid in the synthesis of a protein molecule, each codon correspond to a single amino acid (stop signal) and the full set of codons is called the genetic code.
• Genetic code

  -        All organisms use 20 aa

  -        Each codon specifies a particular aa
• Translation

  -        Creating the amino acid sequence

  -        The language of nucleic acids in translated into the language proteins

  -        Nucleic acids have 4 letter language

  -        Proteins have 20 letter language
• The “Players”

  Messenger RNA (mRNA)

  Ribosomes

  Transfer RNA (tRNA)

  Amino Acids
• Translation has 3 steps

  -        Initiation

  -        Elongation

  -        Termination
• PARTS OF EXCRETORY SYSTEM

  • vena cava
  • renal vein
  • ureter
  • aorta
  • renal artery
  • kidney
• Kidneys

  -        major organs of body excretion

  -        its function unit is called nephron, it produces urine and is the primary unit of homeostasis in the body.

  -        It is a long tubule with a series of blood vessels. The upper end of the tubule is an enlarged cuplike structure called the Bowman’s capsule.
• Ureter

  -        A tube that carries urine from kidneys to urinary bladder.
• Urinary bladder

  -        A temporary storage reservoir of urine, located in pelvic cavity posterior to the symphysis pubis and below the parietal peritoneum.
• Urethra

  -        A fibro muscular tube at the lower opening of the bladder to the pelvic and urogenital diaphragm to outside body called urethral orifice.

  -        also connects to the ductus deferens in males for the ejaculation of sperms.