Cell Structure and Function Quiz

Cell Structure and Function

• Life evolved over billions of years, starting with simple precursors leading to complex multicellular organisms. The basic unit of life is the cell.
• Cells are the fundamental structural and functional units of living organisms.
• Robert Hooke discovered cells.
• Multiple cells work together to form tissues and organs.
• Cellular respiration is the process where food is broken down in mitochondria to produce energy. Cells use glucose from food to produce energy.

Cell Types

• Cells are classified into two main types: Prokaryotic and Eukaryotic.
• Prokaryotic cells are simpler, lacking a defined nucleus.
• Eukaryotic cells are more complex, with a defined nucleus and membrane-bound organelles.

Eukaryotic Cell Structure

• Eukaryotic cells have a cell membrane.
• They contain membrane-bound organelles.
• The nucleus has a nuclear membrane.

Cell Membrane

• The cell membrane is the outer covering of a cell.
• It's composed of a phospholipid bilayer.
• The cell membrane is selectively permeable.
• Its structure is described by the fluid mosaic model.
• Molecules like carbon dioxide and oxygen move across the membrane by diffusion.
• Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.

Cellular Transport

• Diffusion is a type of passive transport.
• Other transport mechanisms include facilitated diffusion and active transport.

Solutions

• Isotonic solutions: Have the same solute and pH concentration as the surrounding fluid (cytoplasm).
• Hypotonic solutions: Have a lower solute concentration than the surrounding fluid. Hypotonic solutions can cause cells to swell or burst due to inward water movement.
• Hypertonic solutions: Have a higher solute concentration than the surrounding fluid. Hypertonic solutions can cause cells to shrink due to outward water movement.

Cell Walls

• Plant cells have cell walls made of cellulose.
• Cell walls provide structural support and protection.
• Cell walls help plant cells withstand hypotonic solutions without bursting.

Cell Organelles

• Eukaryotic cells contain various membrane-bound organelles with specific functions.
  • Examples: Nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, and plastids.
  • Organelles are structures found in the cytoplasm responsible for various functions.
• The nucleus is the control center and contains DNA.
• The nucleus is double-membrane-bound, and has pores that allow for the passage of materials between the nucleus and the cytoplasm.
• Chromosomes are the DNA structures within the nucleus. Humans have 23 pairs.
• Chromatin is a threadlike structure of DNA and proteins that makes up chromosomes. Chromatin condenses into chromosomes during cell division.
• Cytoplasm is the fluid found inside the cell. It provides structure to the cell, and houses different organelles.
• Endoplasmic reticulum: Plays a role in protein synthesis, modification, and transport. Also involved in lipid metabolism and detoxification.
• Rough ER: Has ribosomes on its surface and is involved in protein synthesis.
• Smooth ER: Lacks ribosomes, involved in lipid metabolism, and detoxification
• Golgi apparatus: Packages and transports proteins within and out of the cell ("post office").
• Lysosomes: Contain enzymes that break down cellular waste products and foreign materials.
• Mitochondria: Responsible for generating ATP, the energy currency of the cell. They have their own DNA (mtDNA).
• Plastids: Found in plant cells. Examples include chloroplasts, where photosynthesis occurs; and leucoplastids, responsible for storing starch.

Plant and Animal Cells

• Plant cells have chloroplasts, cell walls, and large central vacuoles, structures absent or small in animal cells.
• Plant cells tend to have a central nucleus, while animal cells' nucleus is usually in the center.

Test your knowledge on cell structure, types, and functions with this quiz. It covers the evolution of life, cellular respiration, and the differences between prokaryotic and eukaryotic cells. Prepare to explore the basics of biology!