LR

WK1_General-Biology-2

Introduction

  • Overview of personal information collection

  • Questions to consider:

    • Name

    • Age

    • Previous school

    • Personal interests

    • Strengths and weaknesses

Classroom Rules

Priority Rules

  • Learning First

    • Make learning a top priority

Following Instructions

  • Obey the Instructions

    • Follow given guidelines to the letter

Respect in the Classroom

  • Respect Everyone

    • Show respect to yourself and others

    • The principle of reciprocity: Give respect to receive respect

Cleanliness and Responsibility

  • Maintain Cleanliness

    • Ensure the classroom is tidy before leaving

    • Keep the area clean for the benefit of all

Deadlines and Accountability

  • Timely Submission

    • Assignments and projects must be submitted on time

    • The motivation behind deadlines: fear of missing a deadline

Nutritional Requirements of Plants and Animals

Nutrition Defined

  • Nutrition

    • The science that interprets nutrients and their roles

    • Encompasses food intake, absorption, assimilation, etc.

Modes of Nutrition

  • Autotrophs vs. Heterotrophs

    • Autotrophs:

      • "Self-feeders"

      • Produce their own food (plants, algae)

      • Can be photoautotrophs or chemoautotrophs

    • Heterotrophs:

      • "Other eaters"

      • Do not create their own food (animals, fungi)

      • Consume other organisms (herbivores, carnivores, omnivores)

Plant Nutritional Requirements

  • Essential elements

    • Macronutrients: required in large amounts (C, H, O, N, K, Ca, Mg, P, S)

    • Micronutrients: required in small amounts (Cl, Fe, B, Mn, Zn, Co, Mo)

Water Transport in Plants

  • Apoplast Pathway

    • Water movement through cell walls

    • Less affected by metabolic activity

  • Symplast Pathway

    • Water and ion transport through plasmodesmata

    • Affected by root's metabolic state

Caloric Content and Animal Nutrition

Definition of Calorie

  • A unit of energy derived from food, defined as the heat needed to raise 1kg of water by 1 degree Celsius.

  • Caloric Values:

    • Carbohydrates: 4 calories/gram

    • Fats: 9 calories/gram

    • Proteins: 4 calories/gram

Energy Balance and Weight Management

  • Isocaloric Balance

    • Maintenance of weight by balancing calories in and out

  • Negative Caloric Balance

    • Weight loss occurs when energy out exceeds energy in

  • Positive Caloric Balance

    • Weight gain results when energy intake exceeds expenditure

Types of Nutrients

Macronutrients

  • Carbohydrates

    • Main energy source

    • Formula: (CH₂O)n

  • Proteins

    • Building blocks of genetic material, made of amino acids

  • Fats/Lipids

    • Store more energy than carbs/proteins

    • Composed of fatty acids

Essential Nutrients

Essential Amino Acids

  • Nine amino acids not synthesized by humans (e.g., methionine, phenylalanine)

Essential Fatty Acids

  • Important for making membrane lipids (e.g., linoleic acid)

Vitamins

  • Organic molecules crucial for metabolism (e.g., Vitamin A, B, C, D)

Trace Elements

  • Inorganic nutrients needed in small amounts (e.g., iodine, zinc)

Mechanisms of Food Uptake in Cells

Types of Endocytosis

  1. Phagocytosis

    • Engulfment of large particles (e.g., bacteria)

  2. Pinocytosis

    • Uptake of extracellular fluid and dissolved substances

  3. Receptor-Mediated Endocytosis

    • Specific solutes enter via receptor recognition

Feeding Mechanisms in Animals

Types of Feeding Strategies

  • Filter Feeding: Collecting nutrients from suspended particles in water

  • Deposit Feeding: Consuming nutrients from soil particles

  • Fluid Feeding: Sucking fluids from other organisms

  • Bulk Feeding: Eating large pieces of food (most animals)

Digestive Systems in Animals

Types of Digestive Systems

  1. Incomplete Digestive System

    • Gastrovascular cavity: single opening for food intake/waste expulsion

  2. Complete Digestive System

    • Tube-like structure with a mouth and anus, specialized organs in between for digestion

Human Digestive System

Main Components

  • Parts: Mouth, esophagus, stomach, small intestine, large intestine, anus, liver, pancreas, gallbladder

  • Functions: Ingestion, digestion (mechanical & chemical), absorption, elimination

Accessory Organs

  • Liver: Produces bile for fat digestion

  • Gallbladder: Stores and releases bile

  • Pancreas: Secretes digestive enzymes

Summary of Digestive Processes

  • Stages: Ingestion -> Digestion -> Absorption -> Elimination

  • The importance of mechanical breakdown for proper digestion