study guide pt 1

Overview of the Test Content

  • There are 60 questions on the test.
  • The test covers chapters one through four.

Enzymes

  • Enzyme Function: Enzymes catalyze chemical reactions.

    • Amino acids in the enzyme's active site interact with substrate molecules to create products.

  • Enzyme Activity Regulation:

    • Enzyme activity is regulated best when specific temperature and pH levels are matched for the enzyme.
    • When temperature exceeds optimal levels, enzymes start to denature and lose functionality.

  • Catalysts:

    • Main characteristic of a catalyst is the increase in reaction rate.

  • Reducing Agents:

    • A reducing agent donates electrons and protons.
    • A molecule that has just donated electrons acts as a reducing agent.

Protein Interactions

  • Conjugated Proteins:

    • A protein combined with another type of molecule, such as a carbohydrate, is described as conjugated.

  • Tertiary Structure of Proteins:

    • Maintained by weak chemical bonds between widely spaced amino acids, as well as disulfide bonds between sulfur groups in cysteines.

  • Structural Proteins:

    • Examples include keratin and collagen, which are classified as both structural and fibrous proteins.

  • Primary Structure of Proteins:

    • The primary structure is the linear arrangement of amino acids in a polypeptide chain.

Cell Biology

  • Junctional Complexes:

    • These are connections that allow epithelial cells to form strong membranes.

  • Centrosome:

    • Responsible for making microtubules, forming cilia, and pulling apart duplicated chromosomes.

  • Neurons:

    • The primary function of neurons is to conduct electrical impulses.

  • Bone Structure:

    • Units of bone composed of concentric rings of lamellae containing trapped osteocytes are called osteons or Haversian systems.

Genetic Concepts

  • Crossing Over:

    • Important for increasing genetic variability during meiosis.

  • Epigenetic Inheritance:

    • Only one allele of a homologous pair is expressed, showcasing the complexity of gene expression regulation.

MicroRNAs

  • MicroRNA:
    • Partially complementary to many messenger RNAs (mRNAs).

Hormonal Regulation

  • Endocrine Secretion:

    • Best example includes testes cells that secrete testosterone into the bloodstream.

  • Insulin Secretion:

    • The primary stimulus for insulin secretion is an increase in blood glucose concentration.

Blood Glucose Levels

  • Normal Range:
    • The normal range of blood glucose concentration after fasting is approximately 70 to 99 mg/dL (milligrams per deciliter).

Metabolic Reactions

  • Endergonic Reactions:

    • These reactions result in a decrease in the amount of entropy in the products, indicative of energy absorption.

  • Sensors in the Body:

    • A decrease in mean arterial pressure is detected by sensors, which play a key role in physiological regulation.