Lesson.2
Cell Structure and Function Notes
Page 4
Biomolecules in Cells
Provide shape and rigidity to cells.
Enable selective permeability for molecules.
Page 5
Distinguishing Major Parts of the Cell
Understanding the structural components of the cell.
Page 6
Learning Objectives
Distinguish structural components of the plasma membrane.
Describe roles of proteins in membranes.
Compare microfilaments, intermediate filaments, and microtubules.
Page 7
Learning Objectives
Describe function and composition of cytoplasm.
Describe structure and function of the cell wall.
Page 8
Overview of Cell Regions
Three major divisions: plasma membrane, cytoplasm, nucleus.
Page 9
Cell Components
Includes membrane-bound and non-membrane-bound organelles.
Key organelles: Rough and Smooth Endoplasmic Reticulum, Golgi Apparatus, Chloroplast, Nucleus, Ribosomes, Vacuole, Mitochondria.
Page 10
Cellular Structures and Processes
Understanding how cellular structures assist in various processes.
Page 11
Plasma Membrane Structure
Primary barrier of the cell.
Composed of lipid bilayer and membrane proteins.
Page 12
Plasma Membrane Composition
Watery environments inside and outside the cell.
Components: Glycoproteins, Glycolipids, Cholesterol, Proteins.
Page 13
Phospholipid Structure
Double layer of phospholipids and proteins.
Hydrophilic heads and hydrophobic tails.
Page 14
Plasma Membrane Components
Composed of glycolipids, glycoproteins, phospholipids, cholesterol, and membrane proteins.
Page 15
Phospholipid Composition
Head region: phosphate group (hydrophilic).
Tail region: two fatty acid chains (hydrophobic).
Page 16
Phospholipid Bilayer
Two layers with phosphate heads facing outward and fatty acid tails inward.
Page 17
Phospholipid Characteristics
Polar (hydrophilic) head interacts with water.
Non-polar (hydrophobic) tail prefers non-polar environments.
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Hydrophilic vs. Hydrophobic
Hydrophilic: forms hydrogen bonds with water.
Hydrophobic: non-polar, avoids water.
Page 19
Plasma Membrane Components
Lipids: Phospholipids, Cholesterol.
Proteins: Integral (receptors), Peripheral.
Carbohydrates: Glycoproteins, Glycolipids.
Page 20
Membrane Protein Functions
Integral proteins act as receptors and activators.
Peripheral proteins assist in various functions.
Page 22
Fluid Mosaic Model
Describes membrane structure as a mosaic of proteins, sugars, and cholesterol.
Fluidity due to viscosity.
Page 23
Factors Affecting Membrane Fluidity
Kinks in fatty acid tails.
Cholesterol regulates fluidity.
Page 24
Selective Permeability
Lipid bilayer allows certain molecules to pass.
Page 25
Permeable Molecules
Small molecules like alcohol, oxygen, nitrogen, and carbon dioxide.
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Impermeable Molecules
Polar molecules like glucose, amino acids, proteins, and nucleic acids.
Page 27
Transport Proteins
Carrier proteins and channel proteins facilitate transport.
Page 28
Types of Membrane Proteins
Channel proteins: passageway for molecules.
Carrier proteins: change shape to transport molecules.
Receptor proteins: detect pathogens and trigger responses.
Page 33
Cytoskeletal Elements
Network of protein fibers providing structural framework.
Observed using fluorescence techniques.
Page 34
Functions of the Cytoskeleton
Provides structural support.
Facilitates movement of organelles and chromosomes.
Page 35
Microtubules
Composed of tubulin proteins.
Radiate from centrosomes and form spindle fibers.
Page 37
Microfilaments
Composed of actin proteins.
Facilitate cell and organelle movement.
Page 39
Intermediate Filaments
Provide structural integrity and maintain cell shape.
Page 40
Cytoplasm Structure
Jelly-like substance where organelles are suspended.
Page 41
Cytoplasm Composition
Composed of cytosol, a semifluid solution of water and molecules.
Page 42
Cell Wall Structure
Rigid structure surrounding the cell membrane.
Maintains cell shape and prevents bursting.
Page 43
Bacterial Cell Wall
Composed of peptidoglycan.
Fungal cell walls consist of chitin.
Page 44
Plant Cell Wall
Composed of cellulose fibers.
Prevents bursting from excess water absorption.
Page 47
Summary of Cell Regions
Plasma membrane: primary barrier, semi-permeable.
Cytoskeleton: support and motility.
Cytoplasm: jelly-like structure with organelles.
Cell wall: rigid structure for protection.
Page 49
Overall Contribution to Cell Survival
Plasma membrane, cytoplasm, cytoskeleton, and cell wall are essential for cell mainten
Major Parts of the Cell
Cell Membrane: Protects the cell and regulates what enters and exits.
Nucleus: Contains genetic material (DNA) and controls cell activities.
Cytoplasm: Jelly-like substance where cellular processes occur.
Mitochondria: Powerhouse of the cell, produces energy (ATP).
Ribosomes: Sites of protein synthesis.
Endoplasmic Reticulum (ER): Involved in protein and lipid synthesis; can be rough (with ribosomes) or smooth (without ribosomes).
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion.
Lysosomes: Contains enzymes for digestion of waste materials.
Centrioles: Involved in cell division and organization of the mitotic spindle.
Definition of ATP
Adenosine Triphosphate (ATP) is a nucleotide that serves as the primary energy carrier in cells. It consists of three phosphate groups, a ribose sugar, and an adenine base. When ATP is hydrolyzed (loses a phosphate group), it releases energy that can be used for various cellular processes, such as muscle contraction, nerve impulse propagation, and biosynthesis. ATP is often referred to as the "energy currency" of the cell.
The major parts of a cell include:
Cell Membrane: Protects the cell and regulates what enters and exits.
Nucleus: Contains genetic material (DNA) and controls cell activities.
Cytoplasm: Jelly-like substance where cellular processes occur.
Mitochondria: Produces energy through cellular respiration.
Ribosomes: Synthesizes proteins.
Endoplasmic Reticulum (ER): Processes and transports proteins and lipids.
Golgi Apparatus: Modifies, sorts, and packages proteins.
Lysosomes: Contains enzymes for digestion of waste materials.