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