Cell molecules and homeostasis_94953beca762bec1ce94d4d2a14cc6c0

Human Anatomy and Physiology Overview

  • Course Title: HAS3165M - Human Anatomy and Physiology for Health Studies Part 1

  • Focus Areas: Cells, Molecules, Homeostasis

Learning Objectives

  • Describe functions of organelles in maintaining homeostasis.

  • Understand structure and function of cellular molecules.

  • Define homeostasis and its importance in stable internal conditions.

  • Understand cell division, protein synthesis, and secretion.

  • Comprehend processes of metabolism and enzymatic reactions.

Key Concepts in Anatomy and Physiology

  • Anatomy: Structures that comprise the body and their interrelationships.

  • Physiology: Functions and mechanisms of body structures.

Primary Food Substances Essential for Life

  • Carbohydrates

  • Lipids

  • Proteins

  • Water

Carbohydrates

  • Composition: Large macromolecules of C, H, and O.

    • Types:

      • Monosaccharides: Simple sugars (e.g., Glucose, Fructose).

      • Disaccharides: Formed from two monosaccharides (e.g., Sucrose, Maltose).

      • Polysaccharides: Long chains of monosaccharides (e.g., Starch, Glycogen, Cellulose).

  • Functions:

    • Energy source; broken down for energy.

    • Energy storage as glycogen in liver/muscles.

    • Structural support in cells, component of DNA/RNA.

Lipids

  • Composition: Made of C, H, O, insoluble in water.

    • Types: Fats (solid) and Oils (liquid).

    • Triglycerides: 3 fatty acids + 1 glycerol.

  • Functions:

    • Energy reserves.

    • Structural components (cell membranes).

    • Metabolic regulators (e.g. hormones).

    • Protection (e.g., around organs).

Proteins

  • Composition: Large molecules of C, H, O, N; built from amino acids.

  • Functions:

    • Immune response (antibodies).

    • Enzymatic function.

    • Signal transmission (messengers).

    • Structural support (cytoskeleton).

    • Transport/storage in cells.

Denaturation of Proteins

  • Process involving modification of protein structure.

  • Causes loss of biological activity; typically occurs due to heat/pH extremes.

  • Factors affecting denaturation: temperature, pH, chemicals, mechanical force.

Water in the Human Body

  • Comprising about 75% of human body weight; plays crucial roles:

    • Solvent: Dilutes waste, medium for reactions.

    • Temperature Regulation: High heat capacity.

    • Transporter: Carries nutrients and waste.

    • Lubricant: Facilitates joint movement and digestion.

Nucleic Acids

  • Function: Storage and expression of genetic information.

    • Types:

      • DNA: Encodes genetic information.

      • RNA: Involved in protein synthesis.

Mineral Salts and Ions

  • Essential for various functions:

    • Calcium: Bone structure, muscle function.

    • Iodine: Component of thyroid hormones.

    • Iron: Key in hemoglobin.

Cells and Tissues

  • Cell: Basic unit of life; capable of specialized functions in multicellular organisms.

  • Cell Structure: Composed of organelles such as the nucleus, mitochondria, and endoplasmic reticulum.

    • Cell Membrane: Selectively permeable barrier, controls material exchange.

    • Cytoplasm: Medium for chemical reactions; contains organelles.

Levels of Organization in the Body

  1. Chemical Level: Atoms and molecules.

  2. Cellular Level: Cells as functional units.

  3. Tissue Level: Groups of similar cells.

  4. Organ Level: Combinations of tissues.

  5. System Level: Organized groups of organs.

  6. Organismal Level: Total living entity.

Types of Tissues

  • Epithelial Tissue: Protective barriers, secretion.

  • Connective Tissue: Support and structure; includes bone, fat, blood.

  • Muscle Tissue: Contraction for movement (skeletal, smooth, cardiac).

  • Nervous Tissue: Transmits signals for communication.

Homeostasis

  • Definition: Automatic process maintaining stable internal conditions despite external changes.

  • Components:

    • Receptor: Detects changes.

    • Control Center: Processes information.

    • Effector: Executes responses.

  • Feedback Mechanisms:

    • Negative Feedback: Reduces excessive responses.

    • Positive Feedback: Intensifies response until endpoint is reached.

Membrane Transport

  • Methods:

    • Passive Transport: No energy required (e.g., diffusion, osmosis).

    • Active Transport: Energy required to move substances against gradient.

  • Types of Passive Transport:

    • Diffusion: Movement from high to low concentration.

    • Facilitated Diffusion: Assisted by protein carriers.

    • Osmosis: Water movement through selectively permeable membranes.

Energy and Metabolism

  • ATP Production: Essential energy currency; powers metabolic processes.

  • Metabolism: Set of chemical reactions for energy and building blocks (includes catabolism and anabolism).

Enzymes

  • Definition: Biological catalysts that speed up reactions without being consumed.

  • Factors Influencing Activity: Temperature, pH, enzyme concentration, substrate concentration, presence of inhibitors.

Protein Synthesis

  • Process: Involves transcription (DNA to mRNA) and translation (mRNA to protein).

  • Involvement of RNA: Different types of RNA play roles in carrying messages and synthesizing proteins.

Protein Secretion

  • Process: After synthesis, proteins undergo folding, modifications, packaging, and are secreted from the cell.