Biology Chapter: Enzymes and Cell Movement

Study Notes

Enzymes

Biological catalysts that speed up chemical reactions
Highly specific to their substrates
Function by lowering activation energy
Examples: amylase breaks down starch, protease breaks down proteins, lipase breaks down fats

Movement in and out of Cells

Diffusion: Passive movement of molecules from high concentration to low concentration
Osmosis: Diffusion of water across a selectively permeable membrane
Active transport: Movement of molecules against their concentration gradient, requiring energy

Characteristics and Classification of Living Organisms

All living things share fundamental characteristics:
- Organization
- Metabolism
- Growth
- Adaptation
- Response to stimuli
- Reproduction
Classification Systems:
- Taxonomy: Hierarchy for organizing living organisms based on shared characteristics
  - Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
- Phylogenetic Tree: Shows evolutionary relationships between organisms

Features of Organisms

Organisms are diverse in form and function
Classified into distinct groups:
- Prokaryotes: Single-celled organisms without a nucleus (bacteria and archaea)
- Eukaryotes: Organisms with a nucleus and membrane-bound organelles (plants, animals, fungi, protists)

Organization of the Organism

Cellular level: Basic building block of life
Tissue level: Groups of similar cells working together
Organ level: Different tissues working together for a specific function
Organ system level: Groups of organs working together
Organism level: All organ systems working together to form a complete living being

Enzymes

Biological catalysts that speed up chemical reactions in living organisms
Highly specific, only catalyzing one or a few reactions
Lower activation energy of reactions, making them occur faster
Work in specific conditions, being sensitive to pH, temperature, and substrate concentration.
Examples include amylase breaking down starch into simpler sugars, and lipase breaking down fats (lipids) into fatty acids and glycerol.

Movement in and out of Cells

Diffusion: Movement of a substance from an area of high concentration to low concentration, to reach equilibrium.
Osmosis: Movement of water molecules from an area of high water potential to low water potential across a selectively permeable membrane, also to reach equilibrium.
Active Transport: Movement of molecules against a concentration gradient, requiring energy from the cell.

Characteristics and Classification of Living Organisms

Seven characteristics of living organisms:
- Movement: Respond to stimuli in their environment
- Respiration: Release energy from food
- Sensitivity: Respond to stimuli in their environment
- Growth: Increase in size and complexity
- Reproduction: Create new organisms of the same species
- Nutrition: Take in and utilize nutrients from the environment
- Excretion: Removal of waste products from the body
Classification Systems: Used to organize living organisms into groups based on shared characteristics.
- Taxonomy: The scientific study of naming, defining, and classifying organisms.
- Binomial Nomenclature: A system of naming species with a two-part name, consisting of the genus and the species.

Concept and Uses of Classification Systems

Hierarchical System: Organizes living things into groups based on shared similarities.
Kingdom, Phylum, Class, Order, Family Genus, Species: Levels of classification, starting with the broadest (kingdom) and becoming increasingly specific.
Phylogenetic Trees: Illustrate the evolutionary relationships between organisms.
Uses of Classification Systems:
- Organization and identification: Helps understand the relationships between different species.
- Communication: Provides a universal language for scientists to communicate about organisms.
- Conservation: Helps identify and protect endangered species.

Features of Organisms

Cells: Basic units of life, each with specific structures performing different functions.
Tissues: Groups of similar cells working together to perform a specific function.
Organs: Composed of different tissues working together to perform a specific function.
Organ Systems: Composed of different organs working together to perform a specific function.
- Systems of organs: Digestive, circulatory, respiratory, nervous, excretory, reproductive, and skeletal systems.

Organization of the Organism

Cellular Level: Individual cells, with their characteristic structures and functions.
Tissue Level: Groups of similar cells, like muscle tissue, nervous tissue, and epithelial tissue.
Organ level: Groups of different tissues working together, such as the stomach, lungs, and brain.
Organ System Level: Groups of organs working together to perform a function, such as the digestive system, which breaks down food.
Organism Level: Complete living being.

Description

Explore the fascinating world of enzymes and their role as biological catalysts. Understand the mechanisms of diffusion, osmosis, and active transport in cells, as well as the characteristics and classification systems of living organisms. Test your knowledge with this interactive quiz on essential biological concepts.