Life Sciences 2 - Exam - Short Answer Questions - Part 1 Flashcards
What is a vaccine and how does it work?
A vaccine is any preparation intended for immunological prevention of disease.
How vaccines work:
The body is exposed to a weakened or dead pathogen.
The body’s immune cells make antibodies to attack the pathogen.
If the body is exposed to the pathogen again, the body will be prepared with antibodies.
Describe the general cellular characteristics of viruses, bacteria, fungi, and parasites.
Viruses: Non-cellular, rely on host cells to reproduce.
Bacteria: Single-celled, prokaryotic, may have a cell wall.
Fungi: Eukaryotic, can be unicellular (yeasts) or multicellular (molds).
Parasites: Organisms that live on or within a host, often causing harm.
Explain the role of bile salts in the digestion and utilization of lipids.
Bile salts emulsify fats in the digestive system, breaking them into smaller droplets that enzymes can more easily digest, aiding in lipid utilization for energy.
Compare the spontaneous generation theory with the germ theory of disease.
Spontaneous generation proposed that life arises from non-living matter, while the germ theory established that microorganisms cause disease.
List two major structural differences between bacterial cells and human cells.
Bacterial cells lack a nucleus and membrane-bound organelles, while human cells have both. Bacteria also have a cell wall, which human cells do not.
Identify the main structural components of carbohydrates, lipids, and proteins.
Carbohydrates: Monosaccharides.
Lipids: Fatty acids and glycerol.
Proteins: Amino acids.
Explain the purpose of Gram staining in microbiology.
Gram staining differentiates bacteria into Gram-positive and Gram-negative, aiding in identification and understanding their cell wall structure.
Describe the concepts of DALY, YLL, and YLD and their relevance in public health.
DALY: Disability-Adjusted Life Years; measures the burden of disease.
YLL: Years of Life Lost; measures premature mortality.
YLD: Years Lived with Disability; measures years spent with illness or disability.
Briefly explain how lipids, carbohydrates, and proteins are digested in the human body.
Carbohydrates: Digested by enzymes like amylase.
Proteins: Digested by proteases.
Lipids: Digested by lipases with bile salts.
Differentiate between antibacterial, antifungal, antiviral, and antiparasitic agents.
Antibacterial: Targets bacteria.
Antifungal: Targets fungi.
Antiviral: Targets viruses.
Antiparasitic: Targets parasites.
List two characteristics each of bacteria, viruses, fungi, and parasites.
Bacteria: Prokaryotic, can reproduce independently.
Viruses: Non-cellular, require a host to reproduce.
Fungi: Eukaryotic, can be multicellular or unicellular.
Parasites: Often eukaryotic, live on/in a host.
Outline the major steps in Koch’s postulates for identifying pathogens.
The microorganism is found in all diseased organisms.
It can be isolated and grown in pure culture.
It causes disease when introduced to a healthy organism.
The microorganism can be re-isolated from the newly infected host.
Explain how enzymes function and why they are important in biological processes.
Enzymes are catalysts that speed up biochemical reactions by lowering activation energy, essential for metabolic processes.
Discuss how competitive and non-competitive enzyme inhibitors differ in their mechanisms.
Competitive: Inhibitor binds to the active site.
Non-Competitive: Inhibitor binds to an allosteric site, changing enzyme shape.
Describe the importance of the Krebs cycle in cellular respiration.
The Krebs cycle generates high-energy molecules (ATP, NADH, FADH₂) that fuel cellular respiration, providing energy for cells.
