Estrutura e Função Celular

Study Notes

Cell Structure and Function

Cells are the basic units of life, containing the fundamental machinery for life processes.
Eukaryotic cells are complex, possessing membrane-bound organelles like the nucleus, mitochondria, and endoplasmic reticulum.
Prokaryotic cells are simpler, lacking these internal membrane-bound compartments.
Cells maintain homeostasis, regulating internal conditions to support life processes.

Cell Membranes

Cell membranes are selectively permeable barriers, controlling the passage of substances in and out of the cell.
Composed primarily of a phospholipid bilayer with embedded proteins.
Fluid mosaic model describes the dynamic nature of the membrane.
Membrane proteins perform various functions, including transport, signaling, and enzymatic activity.
Passive transport processes like diffusion and osmosis move substances down their concentration gradients, requiring no energy.
Active transport processes, like pumps, move substances against gradients, requiring energy.

Cellular Organelles

Nucleus: Contains the cell's genetic material (DNA) and controls cellular activities.
Mitochondria: Powerhouses of the cell, responsible for generating ATP through cellular respiration.
Endoplasmic reticulum (ER): Involved in protein synthesis and lipid metabolism. Rough ER has ribosomes, smooth ER lacks them.
Golgi apparatus: Processes, modifies, and packages proteins and lipids.
Ribosomes: Sites of protein synthesis.
Lysosomes: Contain enzymes for intracellular digestion.
Vacuoles: Involved in storage and transport.
Cytoskeleton: Provides structural support and facilitates cell movement. Includes microtubules, microfilaments, and intermediate filaments.

Cellular Processes

Cell division: Mitosis is a process of cell division resulting in two identical daughter cells, crucial for growth and repair. Meiosis involves two rounds of division creating specialized sex cells.
Cellular respiration: A metabolic process that converts glucose into usable energy in the form of ATP.
Photosynthesis (if applicable): The process by which plants and some other organisms convert light energy into chemical energy in the form of glucose.
Protein synthesis: The process of assembling proteins from amino acids according to genetic instructions. Involves transcription and translation.
Cell communication: Cells communicate with each other through various mechanisms, including signaling pathways and cell recognition.
Apoptosis: Programmed cell death, a crucial process for development and tissue homeostasis.

Cell Types

Different cell types perform specialized functions in multicellular organisms.
Examples include nerve cells (neurons), muscle cells, epithelial cells, and blood cells.
Different cell differentiation patterns are critical for organ development and functioning.

Cell Biology Techniques

Microscopy: Light microscopy and electron microscopy allow visualization of cellular structures.
Cell culture: Allows study of cells outside the body in controlled conditions.
Molecular biology techniques: PCR, gel electrophoresis, Western blotting aid in investigating cellular processes.

Cell signaling

Cells interact with their environment and each other through numerous signaling pathways.
Signal transduction pathways convert extracellular signals into intracellular responses.
Hormones, neurotransmitters, and other signaling molecules play central roles.

Description

Este questionário explora os conceitos básicos sobre a estrutura e função das células. Aborda a diferença entre células eucarióticas e procarióticas, a composição das membranas celulares e os processos de transporte. Teste seus conhecimentos sobre a biologia celular e como as células mantêm a homeostase.