Cell Structure and Function Overview

Study Notes

Cell Structure and Function

Cells are the basic units of life, exhibiting a wide range of shapes and sizes.
Prokaryotic cells (e.g., bacteria) lack a nucleus and membrane-bound organelles.
Eukaryotic cells (e.g., animal and plant cells) possess a nucleus and various membrane-bound organelles.
Key organelles include the nucleus (containing DNA), mitochondria (energy production), endoplasmic reticulum (protein synthesis), Golgi apparatus (modifying and packaging proteins), and lysosomes (waste disposal).
Plant cells, distinct from animal cells, often contain a cell wall, chloroplasts (photosynthesis), and a large central vacuole.
Differences in cell structures relate to specific functions and adaptations for survival in particular environments.

Cell Membrane

The cell membrane is a selectively permeable barrier that regulates what enters and exits the cell.
Composed primarily of a phospholipid bilayer with embedded proteins.
Proteins facilitate transport, act as receptors, and maintain cell structure.
Passive transport (diffusion, osmosis) moves substances across the membrane without energy input.
Active transport moves substances against their concentration gradient requiring energy.

Cellular Respiration

Cellular respiration is the process by which cells release energy from glucose to produce ATP, the cell's energy currency.
The process involves Glycolysis, the Krebs Cycle and the Electron transport chain.
Glycolysis occurs in the cytoplasm, breaking glucose into smaller molecules.
The Krebs cycle (citric acid cycle) and electron transport chain take place in the mitochondria, releasing more ATP.
Aerobic respiration requires oxygen; anaerobic respiration (fermentation) occurs without oxygen, producing less ATP.

Photosynthesis

Photosynthesis is the process by which plants and other organisms use light energy to convert carbon dioxide and water into glucose.
The process takes place in chloroplasts.
Light-dependent reactions capture light energy, creating ATP and NADPH.
Carbon fixation (Calvin cycle) utilizes ATP and NADPH to produce glucose using carbon dioxide.
Photosynthesis is crucial for producing food for most ecosystems.

Genetics

DNA carries genetic information in a double helix structure.
Chromosomes are structures that contain DNA and proteins, organizing the DNA within the cell.
Genes are segments of DNA that code for specific proteins.
Inheritance patterns of genes affect traits and characteristics in organisms.
Mutations are changes in DNA sequences that can lead to variations in traits.

Evolution

Evolution is the change in heritable characteristics of biological populations over successive generations.
Natural selection is a key mechanism of evolution, where organisms with advantageous traits are more likely to survive and reproduce.
Adaptation refers to traits that improve an organism's survival and reproduction in a specific environment.
Speciation involves the formation of new species from existing ones.

Ecology

Ecology studies the relationships between organisms and their environment.
Levels of organization include populations, communities, ecosystems, and the biosphere.
Biomes are large areas with similar climates and dominant plant life.
Nutrient cycles and energy flow are critical aspects of ecosystem functioning.
Organisms interact with each other through competition, predation, and symbiotic relationships.

Biological Diversity

Biodiversity encompasses the variety of life on Earth at all levels, from genes to ecosystems.
High biodiversity is vital for ecosystem stability and resilience.
Threats to biodiversity include habitat loss, pollution, and climate change.
Conservation efforts aim to protect biodiversity and maintain healthy ecosystems.

Biochemistry

Biochemistry investigates the chemical processes occurring within and related to living organisms.
Key macromolecules include carbohydrates (sugars), lipids (fats), proteins, and nucleic acids (DNA and RNA).
Enzymes act as biological catalysts, speeding up chemical reactions in living systems.
Metabolic pathways are series of chemical reactions that build or break down molecules.

Description

Explore the fundamentals of cell structure and function with this quiz. Understand the differences between prokaryotic and eukaryotic cells, key organelles, and the role of the cell membrane. Perfect for biology students looking to strengthen their knowledge.