Genetics Mini Exam I: The Nature of the Information Contained in Genes

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  1. Gene expression is ???
    the process by which the information contained in a gene is utilized by the cell
  2. A single DNA molecule carries a large number of genes

    Kilobase pair: __ bp
    Megabase pair: __ bp
    • 1000
    • 1 million
  3. Genes are separated from one another within the DNA molecule by __
    intergenic DNA
  4. Explain a discontinuous gene.
    In a discontinuous gene, the sections containing biological information are called exons and the intervening sequences are referred to as introns, with introns being longer than exons in most
  5. In the longest genes, the introns added together make up over __% of the length of the gene
  6. Gene expression requires the __, which participate in the series of events that make up __
    • use of enzymes and other kinds of proteins
    • gene expression
  7. Gene expression is a two stage process:
    • Transcription: synthesis of mRNA
    • Translation: synthesis of a protein
  8. Transcription
    For some genes, the RNA transcript is the end product of gene expression. For others, it is a short-lived message that gets translated
  9. Translation
    Each triplet of adjacent ribonucleotides specifies a single amino acid of the protein, the identity of the amino acid corresponding to each triplet being set by the genetic code
  10. Proteins with different amino acid sequences have __ that allow them to __. Some can be __, known as __ (function?) Ex: collagen and keratin
    • different chemical properties
    • play a variety of roles
    • fibrous proteins
    • structural proteins
    • give rigidity to the framework of the organism
  11. Motor proteins
    Motor proteins have amino acid sequences that give them flexibility and allow them to change shape, allowing movement
  12. Enzymes
    Enzymes are proteins with catalytic capability for cellular reactions that bring about the release and storage of energy and the synthesis of new compounds
  13. Other proteins have __ and carry compounds around the body, such as __ and __. 

    Some act as __
    • transport function
    • hemoglobin
    • serum albumin (transports fatty acids_

  14. Others have __ and guard against __ and __
    Regulatory proteins control __activities, such as __(3)__.
    • protective functions
    • infectious agents and injury
    • cellular
    • insulin, somatostatin, and somatotrophin
  15. Only a small fraction of a cell’s RNA is __; the rest is __.
    • mRNA
    • noncoding RNA
  16. What is noncoding RNA?
    molecules that are not translated into protein but instead play direct roles in the cell as RNA

    comprises a few types of molecules
  17. What are the types of noncoding RNA?
    • rRNA
    • tRNA
    • snRNA
    • snoRNA
    • scRNA
    • miRNA
  18. rRNA

    rRNA: the most abundant RNA, which are components of ribosomestRNA is involved in protein synthesis, carrying amino acids to the ribosome and ensuring these are linked together in the order specified by the nucleotide sequence of the mRNA that is being translated
  19. snRNA
    snRNA is found in the nucleus and is involved in RNA splicing, the process by which copies of introns are removed from mRNA molecules and exons are joined together
  20. snoRNA
    snoRNAs are found in the nucleolus; extra chemical groups must be added to rRNA molecules before they can be assembled into ribosomes, and snoRNAs aid this process
  21. scRNA
    scRNAs are a diverse group including molecules involved in the transport of secreted proteins out of the cell
  22. miRNA
    miRNAs and siRNAs are both involved in gene expression, causing certain mRNAs to be silenced so that they cannot be translated, possibly by attaching to these mRNAs through base pairing and causing degradationthis is RNA interference
  23. Why are biological characteristics variable?
    because the genes that code for these characteristics are themselves variable
  24. Alleles
    Alleles are variants of a biological characteristic Example provided through wrinkled and round peas
  25. Some genes come in a whole range of variant forms

    Ex: CFTR: ?????
    cystic fibrosis transmembrane regulator protein—a membrane-bound protein involved in transport of chloride ions into and out of human cells250 kb, mostly due to 26 introns
  26. Three common variants of CFTR result in defective proteins that may give rise to cystic fibrosis

    Name the first.
    In the most common variant, three nucleotides are deleted, resulting in the loss of an amino acid and a change in the function, preventing the protein from attaching to the cell membrane. Therefore, it will not be able to carry out its function
  27. Three common variants of CFTR result in defective proteins that may give rise to cystic fibrosis

    Name the second
    There is another variant of the CFTR gene in which the nucleotide at position 1624 is changed from G to a T, leading to a SNP, causing the mRNA to be degraded so no cystic fibrosis transmembrane regulator protein is made
  28. Three common variants of CFTR result in defective proteins that may give rise to cystic fibrosis

    Name the third
    Another variant has a SNP at position 1651, which does not affect the length of the protein but rather the amino acids, and thus altering the kinetic properties of the protein so that it now transports chloride ions at only 4% the rate displayed by the normal protein
  29. True or False:
    There are other variants of CFTR that do not affect the ability of the gene to give rise to a functional protein
  30. haplotype
    A haplotype describes a sequence variant of a gene
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Genetics Mini Exam I: The Nature of the Information Contained in Genes
2015-09-06 23:57:47
Mini exam
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