Chapter 1-3: Intro to Molecular Biology

• Describe structure and function:

  • Cell membranes: 

    • Structure: double layer of phospholipids together with proteins

    • Function: regulates the transport of materials entering and exiting the cell, only allows certain molecules to pass, adhesion, structural support of the cell

  • Nucleic acids: 

    • Structure: five-carbon sugar, one to three phosphate groups, a single nitrogenous base

    • Function: storing genetic information, protein synthesis, gene expression regulation

  • Proteins: 

    • Structure: chains of amino acids

    • Function: structural scaffolds in cells, enzymes (facilitate chemical reactions), cellular transporters, process regulation, cell recognition, communication

  • Amino acids: 

    • Structure: amine group, carboxyl group, side groups (R groups) and connected by peptide bonds

    • Function: protein synthesis, structural support, primary building blocks of proteins, enzymes and hormones

• Compare and contrast the structure of prokaryotic and eukaryotic cells

  • Prokaryotic: Nucleic region, plasma membrane, DNA, ribosomes, and cytoplasm

  • Eukaryotic: Plasma membrane, nucleus, DNA, cytoplasm, and ribosomes

• Describe the advantages of bacteria as a model organism

  • simple cellular structure, rapid growth rate, ease of genetic manipulation, and ability to be cultured in large quantities under controlled laboratory conditions

• Describe the advantage of yeast as a model organism

  • simple nutritional requirements, rapid growth rate, well-characterized genome, ease of genetic manipulation, and the conservation of many fundamental eukaryotic cellular processes

• Define:

  • Haploid: presence of a single set of chromosomes in an organism's cells

  • Diploid: containing two complete sets of chromosomes, one from each parent

  • Polyploidy: an organism has more than two complete sets of chromosomes in its cells

  • Genotype: The genetic makeup of an organism

  • Phenotype: The visible or measurable effect of the genotype

  • Wild-type: The original or “natural” version of a gene or organism

  • Mutant: Altered version of wild-type allele 

• Compare/contrast the two types of nucleic acids

  • DNA is typically double-stranded and contains the sugar deoxyribose

    • Double helix, two complementary strands, bases: adenine, thymine, cytosine, and guanine

    • Stores genetic information in the cell

  • RNA is usually single-stranded and contains the sugar ribose

    • Single-stranded, bases: adenine, uracil, cytosine, and guanine. 

    • It has a crucial role in protein synthesis with mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA)

• Identify the three components of a nucleotide

  • 1) a nitrogenous base

  • 2) a pentose sugar (five-carbon sugar)

  • 3) a phosphate group 

• Differentiate between: a) purine/pyrimidine and b) nucleotide/nucleoside

• Describe the central dogma of molecular biology

  • a theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein

• Define:

  • Replication: Duplication of DNA prior to cell divisio

  • Transcription: Process by which information from DNA is copied into its RNA equivalent

  • Translation: Making a protein using the information provided by messenger RNA.

  • Melting temperature: The temperature at which the two strands of a DNA molecule are half unpaired

• Describe Chargraff’s rule

  • in any DNA molecule, the amount of adenine (A) is always equal to the amount of thymine (T), and the amount of guanine (G) is always equal to the amount of cytosine (C)

• Describe the 4 levels of protein structure

  • Primary structure: the amino acid sequence of its polypeptide chain

  • Secondary structure: the local spatial arrangement of a polypeptide's backbone (main chain) atoms

  • Tertiary structure: the three-dimensional structure of an entire polypeptide chain

Quaternary structure:  the three-dimensional arrangement of the subunits in a multisubunit protein