Cells The Basic Unit of Life A Smallest

Cells – The Basic Unit of Life A. Smallest unit that has ALL the characteristics of life 1. Grow 2. Respond to a stimuli 3. Reproduce 4. Metabolism 5. Move 6. Homeostasis

B. Several types of cells 1. Variety of shapes 2. Variety of sizes Cell structure determines function Cell function determines structure

C. Functions of the cell 1. 2. 3. 4. 5. Basic unit of life Protection & support Movement Communication Cell metabolism & energy release D. 70 – 80% Water E. Two areas of water Intracellular-inside the cell Extracellular- outside the cell

1. Extracellular ►Thick, syrup-like liquid ►Mixture of dissolved gases, salts, food & cellular products manufactured or synthesized by mechanisms inside the cell, which leave by secretion. ex. hormones, vitamins, & proteins

Types A. Contained within blood vessels & chambers of the heart Plasma -liquid medium for transport (Oxygen, wastes, & nutrients). B. Interstitial Fluid Pathway for products that are in route between cells. C. Extracellular Matrix---ECM---composed of proteins and polysaccharides

Purpose of ECM- Structural support for the body Other Functions

2. Intracellular Environment Between Cells ►Protoplasm or Cytoplasm ► Components – Water Fats Proteins Nucleic Acids Carbohydrates Electrolytes

When the components are organized in such a way you get: Characteristics of life

Boundary of the cell or Cell (Plasma) Membrane ► 3 major components inside the cell 1. Intracellular fluid - cytoplasm or protoplasm 2. Organelles - small membrane bound vessels 3. Nucleus - regulates the cell activities

Review ► Name three characteristics of life? ► How is intracellular material different from extracellular material? ► How is interstitial fluid different from extracellular fluid?

II. Cell Membrane A. Bilipid layer 1. Composed of two phosolipids layers 2. Glycoproteins 3. Proteins a. Integral b. Peripheral 4. Cholesterol 5. Glycolipids 6. Membrane receptors 7. Carrier molecules 8. Receptor molecules

B. Fluid Mosaic Model C. Semi Permeable- Selective permeable Not everything can pass through the cell membrane. 2. Materials that pass with ease a. Water b. Small lipid soluble molecules c. Small non charged particles

3. Materials that have difficulty passing: a. Larger molecules (lipid soluble or non lipid soluble) b. Charged particles c. Need carrier proteins to pass through the cell membrane.

4. Two ways materials can pass through the cell membrane a. Passive – no energy required Following a concentration gradient from high to low to establish equilibrium. Majority of life’s process. b. Active – requires energy Going against the concentration gradient trying NOT to establish a equilibrium Nerve cells

5. Ways that material can pass through the cell membrane. a. Directly b. Membrane channels c. Carrier molecules d. Vesicles

Review ► Describe the structure of the cell membrane. ► What function does it perform? ► How do lipid-soluble molecules, small molecules and large molecules that are not lipid base cross the cell membrane? ► How is passive movement different from active movement?

D. Types of Passive movement 1. Simple Diffusion - Following a concentration gradient from high to low to establish equilibrium. Small lipid soluble & Non charged particles

2. Facilitated Diffusion Following a concentration gradient from high to low to establish equilibrium. Larger & charged particles Need Carrier proteins

3. Osmosis – Diffusion of water across a semipermeable membrane. a Types of osmosis 1. Isotonic Solution – Equal movements of water into and out of the cell due to equal solute concentrations. 2. Hypertonic – More movement of water out of the cell then in due to more solutes out of the cell. 3. Hypotonic – More movement of water into the cell then out due to more solutes in the cell

Review How is simple diffusion different from facilitated diffusion? What would happen to cells that are placed in the following solutions: isotonic, hypertonic, hypotonic.

E. Active transport Requires energy - ATP Going against the concentration gradient trying NOT to establish equilibrium Ex. Sodium – Potassium Pump

F. Cytosis – Movement of molecules across the cell membrane by forming a vesicle and requiring ATP. 1. Two types a. Exocytosis – Materials leaving the cell. b. Endocytosis – Materials entering the cell. 1. Phagocytosis – Engulfing large solid particles “cellular eating” 2. Pinocytosis – Engulfing liquids. “cellular drinking”

Movement of Materials Review

Review ► How are facilitated diffusion and active transport similar and how are they different? ► How are phagocytosis, pinocytosis, endocytosis, and exocytosis similar and how are they different?

III. Cytoplasma and Organelles of the cell. A. Cytoplasma – between the cell membrane & nucleu 1. Cytosol a. water b. proteins c. organic compounds d. inorganic compounds 2. Organelles small compartments that do a particular function

B. Types of organelles 1. Endoplasmic reticulum (ER) – series of membrane folds a. Two types Rough (ER) – Hold ribosomes – protein production Smooth (ER) – No ribosomes – Lipid synthesis (hormones), detoxification. 2. Golgi Body – series of membrane folds Packaging and shipping of proteins

3. Mitochondria – a. Produces energy for the body in the form of ATP. b. Two lipid membranes. 1. Inner – Cristae 2. Space – Matrix c. Own DNA 4. Lysosomes – Contain enzymes to break apart intracellular particles. 5. Peroxisomes – Contains enzymes to detoxify only in the presence of oxygen.

6. Nucleus – “Control center” a. Round. b. Largest part of the cell. c. Contains genetic material of the cell DNA & RNA d. Components 1. Nuclear membrane * bilipid layer * pores for movement 2. Nucleoplasm – similar to cytosol * Nucleoli – composed of RNA and proteins. * Chromatin -Thin strands of DNA wrapped around proteins balls called histones. -Contains genes

7. Cytoskeleton – proteins that support the cell, hold organelles & allows the cell to change shape. Microtubules – hollow structure made of protein sub-unit. (large) 1. Cell division 2. Form flagella & cilia 3. Cytoskeleton Microfilament - cellular movement. Filaments(small) Intermediate – Filaments (between) Ex. Centrioles – helps the cell with cellular division. 8. Cilia 9. Flagella 10. Microvilli

Organelle Review

Review ► What is the organelles: golgi SER RER function of the following ribosome mitochondria cilia flagella Why is the nucleus referred to as the “control center” of the cell?

IV. Protein Synthesis A. Genetic Code 1. Based on the genetic code. 2. Code from your DNA which contains genes. 3. DNA is made up of nucleotides. 4. Nucleotides are in groups of three – codons.

B. First Step in Protein synthesis 1. Transcription a. Copying DNA into RNA b. Protects the master copy 2. Three type of RNA a. Messenger RNA – m. RNA Contains the message on how to make the protein. b. Transfer RNA - t. RNA Transfers the AA to build the protein. - Contains anticodons. c. Ribosomal RNA – r. RNA Site of protein production Composed of large and small subunits.

C. Second Step in Protein Synthesis 1. Translation a. Copying RNA into Proteins b. Requires all the types of RNA 2. Steps 1. m. RNA binds to r. RNA 2. The two subunits come together. 3. t. RNA with the AA must match up the ANTICODON to the CODON of the m. RNA. 4. Process repeats and peptide bond forms between the AA until the entire protein is produced.

Transcription, Translation Review

Review ► What is a gene? ► What process do the cell copy DNA into RNA? Why? ► What role does m. RNA play in transcription?

V. Cell Division A. Two types 1. Mitosis – Nuclear division a. Exact copies of cells are produced. b. Purpose 1. Growth 2. Maintenance 3. Repair c. Diploid to diploid.

d. Stages 1. Interphase – cells grows. DNA duplicates. 2. Prophase – Nuclear membrane breaks down. Centrioles move to opposite poles. Chromosomes form. 3. Metaphase – Chromosomes line up at the cells equator. 4. Anaphase – Chromosome separate 5. Telophase – Reverse of prophase. 6. Cytokinesis – Cytoplasm and organelles divide

Mitosis

2. Meiosis – Gamete production a. Cells are no longer exact copies. b. Diploid to haploid. c. Purpose 1. Sexual reproduction

1. Interphase 2. Prophase I 3. Metaphase I 4. Anaphase I 5. Telophase I 6. Interkineses 7. Prophase II 8. Metaphase II 9. Anaphase II 10. Telophase II

VI. Cellular Aging A. Cellular Senescence 1. Irreversible changes within the cell. a. Graying b. Wrinkles c. Accumulation of body fat d. decreased muscle tone e. Loss of agility f. Slowing of mental ability. B. Two theories on aging 1. Genetic – RUN OUT OF GAS 2. Environmental – FREE RADICALS.