Notes, summaries, assignments, exams, and exercises for Biology for University

Proteins: Composition and Structure

Proteins consist of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), and may also contain sulfur (S), phosphorus (P), iron (Fe), magnesium (Mg), and copper (Cu). Proteins are made up of smaller molecules called amino acids, which are linked by peptide bonds.

Amino Acids and Their Properties

Amino acids with uncharged polar side chains are hydrophilic and are usually found on the outside of the cell. Nonpolar side chains tend to aggregate in the interior.

Peptide Bonds and Polypeptides

Amino acids are commonly attached through amide links, called peptide bonds. The union of multiple amino acids results in a peptide. A peptide with fewer than 10 amino acids is called an oligopeptide, and if it contains more...

Background

Medical History

• Morbid background
• Chronic respiratory diseases (presence or absence)
• Thoracic surgery history
• Injuries

Reproductive History

• Relevant for therapeutic and diagnostic decisions
• Reproductive age
• Contraceptive methods
• Catamenial regimen

Habits

• Crucial for diagnosis
• Snuff: type, frequency, duration, mode, passive exposure
• Pack-years (e.g., 1 pack/day for 1 year = 1 pack-year)
• Alcohol consumption
• Animal breeding (mammals, birds)
• Biomass fuel use

Drug Use History

• Impact on diagnosis and treatment
• Effects on bronchial kinetics
• Effects on lung morphology
• Influence on respiratory comorbidities

• ACE inhibitors
• Beta-blockers (e.g., propranolol)
• Antineoplastics (e.g., bleomycin, doxorubicin)
• Antiarrhythmics (e.g., amiodarone)
• Nitrofurantoin, methotrexate
• Calcium,

Understanding Myiasis: Larval Infestations

General Overview of Myiasis

Larvae develop and, upon reaching the third stage, can be released through a sneeze. These infestations can cause significant economic losses in livestock. At the human level, sanitary issues often occur in people in contact with cattle. Larvae released onto the eyes can cause external ocular myiasis. While often benign, it is very annoying because the larvae produce irritation at the level of the conjunctiva and cornea.

Hypodermatidae Family: Cattle Grubs

The Hypodermatidae family includes various Hypoderma genera, some with significant health implications, such as Hypoderma bovis (major cattle grub) and Hypoderma lineatum (minor cattle grub).

Life Cycle of Hypodermatidae

Adults,...

Pulmonary Ventilation and Gas Exchange

Mechanical pulmonary ventilation involves the movement of air. A single breath consists of alveolar dead space, air, and water vapor.

• Functional Residual Capacity of the Lungs: 2300 ml
• Normal Alveolar Ventilation: 4.2 L/min
• Diffusion of O2 at Rest: 21 ml/min/mmHg (65 during exercise)
• Diffusion of CO2 at Rest: 400 to 450 (1200 to 1300 during exercise)

The Va/Q ratio represents the ventilation-perfusion equivalent. A value of zero indicates no ventilation, while infinite indicates no perfusion.

Erythropoiesis and Blood Components

Erythropoietin is a protein stimulating the production of erythrocytes. The primary regulator of red cell production is tissue oxygenation.

An agglutinogen is the antigen which recognizes...

Abdominal Wall Anatomy: Key Structures

Bony Landmarks

• Sternum
• 4th Rib
• Vertebrae
• Ilium
• Ischium

Muscles of the Abdominal Wall

Anterior and Lateral Muscles

• Pectoralis major
• Serratus anterior
• External oblique abdominis
• Internal oblique abdominis
• Latissimus dorsi
• Rectus abdominis
• Pyramidalis
• Cremaster (in males)
• Transversus abdominis
• Diaphragm (superior aspect)
• Teres major
• Rhomboids
• Trapezius

Posterior Muscles

• Quadratus lumborum
• Psoas major
• Psoas minor
• Piriformis
• Ischiococcygeus
• Obturator internus
• Levator ani

Vasculature of the Abdomen

Arteries

Anterior Wall & Related Arteries

• Axillary artery
• Subclavian artery
• Subscapular artery
• Internal thoracic artery (lateral to the sternum)
• Lateral thoracic artery (under the arm)
• Thoracodorsal artery
• Anterior intercostal arteries
• Musculophrenic

Staphylococcus

• Easily develops antimicrobial resistance
• Gram-positive cocci
• Catalase-positive
• Facultative anaerobes
• Not demanding in their nutritional requirements
• Grow in normal media
• Some pathogenic species are generally opportunistic pathogens, commensals
• Important in animal and human infections

Natural Habitat

Widespread in nature; found on human and animal skin, surfaces of objects, air, soil, water, and milk.

S. aureus

Main pathogen associated with infections; colonizes nasal passages and pharynx.

S. epidermidis

Produces skin lesions, wound infections; microbiota found in the skin, respiratory tract, and gastrointestinal tract.

S. saprophyticus

Associated with urinary tract infections.

Immunogens

• Polysaccharide A (specific for S. aureus)
  • Antiphagocytic
  • Antiplatelet
  • Activator

Physiological Control of Digestion and Essential Vitamins

Innervation of Chewing

• Afferent Nerves: Trigeminal (V pair)
• Efferent Nerves:
  • Trigeminal motor branch: Jaw elevator muscles, digastric muscle
  • Facial (VII pair): Lips and cheeks
  • Hypoglossal (XII pair): Tongue

Regulation of Swallowing

• Afferent Nerves:
  • Glossopharyngeal (IX pair): Tongue
  • Pharyngeal branch of Vagus (X pair)
  • Maxillary division of Trigeminal (V pair): Mouth
• Efferent Nerves: Trigeminal, Glossopharyngeal, Vagus, Spinal Accessory (XI pair), Hypoglossal
  • Targets: Tongue, laryngeal muscles, vocal cord adductor muscles

Regulation of Gastric Juice

• Nervous Regulation:
  • Parasympathetic: Acetylcholine-stimulated
  • Sympathetic: Adrenaline-inhibited
• Humoral Regulation:
  • Stimulatory: Gastrin, Secretin, Histamine
  • Inhibitory

Heart Failure

Heart failure is the inability of the heart to pump sufficient blood volume into the peripheral circulation, resulting in a diminished cardiac output.

Classification

Location: Left, right, or general.

Pathophysiological Impact:

• Anterograde Heart Failure: Reduced volume expelled.
• Retrograde Heart Failure: Increased resistance to pumping.

Presentation: Acute or chronic.

Etiology

• Cardiac Ischemia and Myocardial Infarction: Affect contractility.
• Valvular and Congenital Heart Disease: Affect pre- and afterload.
• High Blood Pressure: Affects afterload.
• Renal Failure: Affects preload.

Mechanisms

• Decreased Myocardial Contractility
• Systolic Overload: Hypertension and valvular stenosis.
• Diastolic Overload: Valvular heart disease and shunt.
• Effects on Myocardium:

enzyme: protein substance in nature that catalyze chemical reactions, as far as possible thermodynamically, are protein molecules that have the capacity to facilitate and accelerate the chemical reactions that occur in living tissues. Enzymes do not react chemically with the substances that act (called substrates) nor alter the balance of the reaction.
classification: the name of the enzyme is the substrate plus the suffix-ase enzyme names indicate the specificity of its function
oxido-reductase catalyze oxidation-reduction reactions, those involving the gain (or reduction) or loss of electrons (or oxidation). The most important are the dehydrogenase and oxidase
transferase: functional 2 groups transferred from one molecule to another: eg...

The Tricarboxylic Acid (TCA) cycle, also called the Krebs cycle or citric acid cycle, is a cyclic series of reactions in which acetyl-CoA is oxidized to CO₂, producing reduced coenzymes NADH and FADH₂ and generating energy.

Energetics

For one acetyl-CoA:

• 3 NADH = 3 × 2.5 = 7.5 ATP
• 1 FADH₂ = 1 × 1.5 = 1.5 ATP
• 1 GTP = 1 ATP
• Total = 10 ATP per acetyl-CoA

Since one glucose produces 2 acetyl-CoA:

TCA yield = 20 ATP per glucose

Importance of the TCA Cycle

• Major pathway for the oxidation of acetyl-CoA.
• Produces ATP and GTP.
• Produces NADH and FADH₂ for the electron transport chain (ETC).
• Provides intermediates for amino acid synthesis.

Enzyme Inhibition

Definition

Enzyme inhibition is the reduction in enzyme activity due to the binding of an inhibitor to...