Cell Biology: Cell Structure

Cell Biology

Cell Structure

• Plasma membrane: semi-permeable membrane separating cell from environment
• Cytoplasm: jelly-like substance inside cell where metabolic reactions occur
• Nucleus: contains genetic material (DNA)
• Mitochondria: generates energy for cell through cellular respiration
• Endoplasmic reticulum (ER): involved in protein synthesis and transport
• Ribosomes: site of protein synthesis
• Lysosomes: contains digestive enzymes for cellular recycling
• Cytoskeleton: provides structural support and shape to cell

Cell Division

• Mitosis: process of cell division resulting in two daughter cells
  • Interphase: cell grows and prepares for division
  • Prophase: chromatin condenses into visible chromosomes
  • Metaphase: chromosomes line up at cell equator
  • Anaphase: sister chromatids separate
  • Telophase: nuclear envelope reforms
  • Cytokinesis: cytoplasm divides and cell splits
• Meiosis: process of cell division resulting in four non-identical daughter cells (gametes)

Cellular Transport

• Passive transport: movement of molecules from high to low concentration
  • Diffusion: random movement of molecules
  • Osmosis: movement of water molecules
• Active transport: movement of molecules from low to high concentration using energy
  • Carrier proteins: transport molecules across membrane
  • Pumping: energy-dependent transport

Microbiology

Microorganisms

• Bacteria: prokaryotic cells lacking nucleus and membrane-bound organelles
• Viruses: infectious particles consisting of genetic material and protein coat
• Fungi: eukaryotic cells with cell walls containing chitin
• Protists: eukaryotic cells that don't fit into other kingdoms (e.g., protozoa, algae)

Microbial Growth and Nutrition

• Growth: increase in number of cells or biomass
• Nutrition: obtaining energy and nutrients
  • Autotrophs: produce own food through photosynthesis or chemosynthesis
  • Heterotrophs: obtain energy by consuming other organisms
• Environmental factors affecting growth:
  • Temperature
  • pH
  • Oxygen availability
  • Nutrient availability

Microbial Interactions

• Symbiosis: close, long-term relationships between different species
  • Mutualism: both species benefit
  • Commensalism: one species benefits, other unaffected
  • Parasitism: one species benefits, other harmed
• Microbial ecology: study of microbial interactions with environment and each other

Cell Biology

Cell Structure

• Plasma membrane is semi-permeable, separating cell from environment
• Cytoplasm is jelly-like, where metabolic reactions occur
• Nucleus contains genetic material (DNA)
• Mitochondria generates energy for cell through cellular respiration
• Endoplasmic reticulum (ER) is involved in protein synthesis and transport
• Ribosomes are the site of protein synthesis
• Lysosomes contain digestive enzymes for cellular recycling
• Cytoskeleton provides structural support and shape to cell

Cell Division

• Mitosis is the process of cell division resulting in two daughter cells
• Interphase is the stage where cell grows and prepares for division
• Prophase is the stage where chromatin condenses into visible chromosomes
• Metaphase is the stage where chromosomes line up at cell equator
• Anaphase is the stage where sister chromatids separate
• Telophase is the stage where nuclear envelope reforms
• Cytokinesis is the stage where cytoplasm divides and cell splits
• Meiosis is the process of cell division resulting in four non-identical daughter cells (gametes)

Cellular Transport

• Passive transport is the movement of molecules from high to low concentration
• Diffusion is the random movement of molecules
• Osmosis is the movement of water molecules
• Active transport is the movement of molecules from low to high concentration using energy
• Carrier proteins transport molecules across membrane
• Pumping is an energy-dependent transport

Microbiology

Microorganisms

• Bacteria are prokaryotic cells lacking nucleus and membrane-bound organelles
• Viruses are infectious particles consisting of genetic material and protein coat
• Fungi are eukaryotic cells with cell walls containing chitin
• Protists are eukaryotic cells that don't fit into other kingdoms (e.g., protozoa, algae)

Microbial Growth and Nutrition

• Growth is the increase in number of cells or biomass
• Nutrition is obtaining energy and nutrients
• Autotrophs produce their own food through photosynthesis or chemosynthesis
• Heterotrophs obtain energy by consuming other organisms
• Environmental factors affecting growth include temperature, pH, oxygen availability, and nutrient availability

Microbial Interactions

• Symbiosis is a close, long-term relationship between different species
• Mutualism is a relationship where both species benefit
• Commensalism is a relationship where one species benefits, other unaffected
• Parasitism is a relationship where one species benefits, other harmed
• Microbial ecology is the study of microbial interactions with environment and each other