UNIT 1: WELLNESS & HOMEOSTASIS Biology notes 1 Mr.Yeung
WHAT IS UNIT 1 ABOUT? Wellness & Homeostasis 0. Wellness (Reading labels/homeostasis/ serving size) 1. Cell Biology (Ch.3) Cell organelles Cell types 2. Membrane structure and Function (Ch.4) 3. Metabolism and Energy (Ch.6) ATP
WHAT DO YOU KNOW ABOUT THE HUMAN BODY? Take each of the organs, tissues, cells, parts of the body and arrange them in their appropriate locations.
CONCEPT MAP OF THE UNIT Understand Read Apply Relate
Enzymes Cell theory Diffusion Energy Membrane Cell origins Cells Eukaryotic Prokaryotic Instruments Organelles Types of microscopes
Do this! 1. Grab a slide and place a drop of methylene blue on it. 2. Take a toothpick and rub it against the insides of your cheeks (don t do it too hard!) 3. Stir the end of the toothpick into the methylene blue 4. Cover the drop with a cover slip 5. Place under the microscope and observe
WHAT DID YOU JUST SEE? Now imagine that you are living the 16th century. What can you tell people what you just saw? http://www.bbc.co.uk/staticarchive/742e4ca780f38fc30d7f645838936c65b92c744f.jpg More importantly, how do you prove and justify your points?
In the past: Spontaneous genera0on Since Aristotle s time (4 B.C), there was an belief that cells magically appeared. Eg) Leave meat out and you ll get maggots This was proved not true by (1765-1767), Lazzaro Spallanzani
What is a cell? The smallest functional and structural living unit of life What does that mean? If we were to break down an organism to the smallest living part, you will see cells.
Red blood cells Nerve cells Plant Cells
WHERE DO CELLS COME Cell theory FROM? 1.All living organisms are composed of one or more cells 2.Cells are the basic functional and structural unit of an organism. 3.All cells must come from pre-existing cells!
1. Use energy 3. Control functions 2. Sense the environment Keep the 6 requirements in mind to fully understand and appreciate cell biology Life s requirements for survival 4. Build and repair 5. Eliminate wastes 6. Reproduce
CELL TYPES Eukaryotic Cell Prokaryotic Cell Can be both unicellular or multicellular Contains a nucleus (with red blood cells as an exception) Unicellular Lacks a membrane-bound nucleus Animal cells, plant cells, fungi and protists are eukaryotes Bacteria are prokaryotic
Eukaryotic Cell Prokaryotic Cell
PROKARYOTIC CELLS Pro - before Karyote - nut or kernal, prokaryotic cells are thought to have existed before eukaryotic cells They lack a true membranebounded nucleus. Contains a cell wall containing peptidoglycan, an unique molecule for bacteria, made from sugar molecules joined together. A plasma membrane still exists
PROKARYOTIC CELLS The peptidoglycan is a key component in designing antibiotics. A capsule further surrounds the cell wall containing a slime layer.
Prokaryotic cells locomotion Contains a long tail called flagella to help bacteria move. Some contains a fimbriae that are tiny arms that stick out to attach to surfaces.
PROKARYOTE S GENETIC MATERIAL Contains a single chromosome in the nucleiod (not surrounded by membranes). Contains plasmids which are small rings of DNA. Smaller ribosomes for protein synthesis.
PROKARYOTE CELL SUMMARY Structure & Locomotion cell wall with peptidoglycan and capsule flagella for locomotion fimbriae for attachement Genetic storage 1 chromosome (circular DNA) located in nucleoid in cytoplasm contains plasmids but not restricted to prokaryotes
EUKARYOTIC CELL ORGANELLES Review of organelles: Nucleus (Nuclear membrane, nucleolus,) Cytoplasm Mitochondria Vacuoles Ribosomes Endoplasmic reticulum (Rough & Smooth) Golgi apparatus Lysosome Cilia Cell membrane
CELL MEMBRANE (CH.4) Key Points: Determines what can come in and leave the cell. Contains a phospholipid bilayer Two layers with a head near the surface and tail inside the bilayer. The head portion is hydrophilic (water loving) while tail is hydrophobic (water fearing) More info on the cell membrane in the next chapter Proteins are scattered around the membrane
NUCLEUS
RIBOSOMES Key Points: Func0on: protein synthesis Composed of rrna + protein Large subunit + small subunit Types: Free ribosomes: float in cytosol, produce proteins used within cell Bound ribosomes: afached to ER, make proteins for export from cell
The next 3 organelles are classified as the Endomembrane system - collectively functions as a regulatory system for proteins and metabolism
ENDOPLASMIC RETICULUM (ER) What it is: Network of membranes and sacs Types: Rough ER: ribosomes on surface Func0on: package proteins for secre0on, send transport vesicles to Golgi, make replacement membrane Smooth ER: no ribosomes on surface Func0on: synthesize lipids, detox drugs & poisons, store Ca 2+
GOLGI APPARATUS Func<on: synthesis & packaging of materials (small molecules) for transport (in vesicles); produce lysosomes Series of flafened membrane sacs (cisternae)
LYSOSOME Func<on: intracellular diges0on; recycle cell s materials; programmed cell death (apoptosis) Contains hydroly<c enzymes
VACUOLES Func<on: storage of materials (food, water, minerals, pigments, poisons) Membrane- bound vesicles Eg. food vacuoles, contrac0le vacuoles Plants: large central vacuole - - stores water, ions
MITOCHONDRIA Func0on: site of cellular respira.on Double membrane: outer and inner membrane Cristae: folds of inner membrane; contains enzymes for ATP produc0on; increased surface area to ATP made Matrix: fluid- filled inner compartment
CILIA AND FLAGELLA Flagella: long and few; propel through water Cilia: short and numerous; locomo0on or move fluids
Endosymbiont theory