BIOL 235 Lab Quiz 7 Topics Notes

BIOL 235 Lab Quiz 7 Topics

Please review your Lt labs and corresponding lab slides to prepare for your lab quizzes. These lab quizzes consist of 10 questions and will be administered promptly at the beginning of the lab session, with a 15-minute time limit for completion.

LAB 13: CARDIOVASCULAR EFFECTS OF EXERCISE

• Parts of ECG (Electrocardiogram)

  • P wave: Represents atrial depolarization (contraction). It's the first positive deflection on the ECG tracing.
  • QRS complex: Represents ventricular depolarization (contraction). It's a series of sharp upward and downward deflections.
  • T wave: Represents ventricular repolarization (relaxation). It's a broad, positive deflection following the QRS complex.
  • PR interval: The time from the beginning of the P wave to the start of the QRS complex, representing the time it takes for the electrical impulse to travel from the atria to the ventricles.
  • ST segment: The segment from the end of the S wave to the beginning of the T wave, representing the period when the ventricles are depolarized.

• Result of exercise on heart rate and pulse amplitude

  • Heart Rate: Exercise increases heart rate due to the body's increased demand for oxygen and nutrients. The sympathetic nervous system is activated, releasing norepinephrine, which increases the firing rate of the sinoatrial (SA) node, the heart's natural pacemaker. This leads to a faster heart rate.
  • Pulse Amplitude: Exercise generally increases pulse amplitude. As the heart pumps more forcefully and frequently, the volume of blood ejected with each beat (stroke volume) increases, leading to a stronger pulse.

• Result of local hand exercise on pulse rate and pulse amplitude

  • Pulse Rate: Local hand exercise will likely cause a localized increase in pulse rate, but not as significant as whole-body exercise. The muscles in the hand require more oxygen during exercise, leading to vasodilation (widening of blood vessels) to increase blood flow.
  • Pulse Amplitude: Local hand exercise will likely increase pulse amplitude in the exercised hand. The increased blood flow to the hand will result in a stronger pulse.

LAB 14: ENZYME FUNCTION

• Biomolecules

  • Carbohydrates: Provide energy. Examples include glucose, fructose, and starch. They are composed of carbon, hydrogen, and oxygen.
  • Lipids: Include fats, oils, and waxes. They store energy, insulate the body, and protect organs. Lipids are composed of carbon, hydrogen, and oxygen, but have a higher proportion of carbon and hydrogen.
  • Proteins: Perform a wide range of functions, including catalyzing reactions, transporting molecules, and providing structural support. Proteins are made of amino acids.
  • Nucleic Acids: Store and transmit genetic information. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are examples. They are composed of nucleotides.

• GI tract and accessory organs

  • GI Tract: A continuous tube that includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus. It's responsible for digesting and absorbing nutrients.
  • Accessory Organs: Organs that assist in digestion but are not part of the GI tract. These include the salivary glands, liver, gallbladder, and pancreas.
    • Salivary glands: Produce saliva, which contains enzymes (such as amylase) that begin the digestion of carbohydrates.
    • Liver: Produces bile, which emulsifies fats, making them easier to digest.
    • Gallbladder: Stores and concentrates bile produced by the liver.
    • Pancreas: Produces pancreatic juice, which contains enzymes that digest carbohydrates, proteins, and fats, as well as bicarbonate to neutralize stomach acid.

• Pepsin action

  • Pepsin: An enzyme produced in the stomach that breaks down proteins into smaller peptides. It is most active in acidic conditions (pH around 2). Pepsin is secreted as an inactive precursor called pepsinogen, which is activated by hydrochloric acid (HCl) in the stomach.
  • Reaction: Proteins + Pepsin + HCL (hydrochloric acid) \rightarrow peptides

• Lab Results: This section would refer to the expected and actual outcomes of the experiments conducted in the lab, specifically focusing on the activity of pepsin under different conditions (e.g., different pH levels, presence or absence of pepsin inhibitors).