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Unit CCycling of Matter in Living Systems

1.1: Microscopes

History

• Hans and Zacharias Janssen • First Compound Microscope

• 2 Lenses

• 1595

• Robert Hooke • 1665 • 3 lenses + light source • Cell- small

• Cell Theory

Antoni van Leeuwenhoek

• Using single lens microscope

• Identified movement of cells • Bacteria

• Protozoa

• Sperm

• Named specimens animalcules

Microscopes

• Microscope: optical device used to view small objects• Has at least 2 lenses (objective lens and eyepiece)

• Compound Light Microscope: microscope that has two or more lenses and light source• Magnifies 400-1000 times normal size

• Electron Microscope: Magnifies 600 000 times • Uses electrons (beam)

How to Use a Microscope

• Microscopes allow you to look at thin slices of an object

• Precision instrument

• Handle with care

• Questions: • How should you prepare your work area? • How should you carry the microscope to your work area?• In what position (upright, tilted) should you keep the microscope?• What parts of the microscope should you keep clean? Why?• How and where should you store the microscope when you’ve finished using

it?

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• Eyepiece: Lens that enlarges image from the objective lens

• Tube: Holds eyepiece and objective lens at correct working distance

• Objective Lens: Magnifies image

• Stage: supports slide (specimen)

• Stage Clips: Holds slide in place

• Course-Adjustment Knob: Brings image into focus. Uses low power objective lens

• Fine-Adjustment Knob: Bings image into focus; used with medium/high power objective lens

• Light Source: Bulb sends light up through specimen (slide)

• Arm and Base: Supports microscope

• Diaphragm: Controls light

Calculating Magnification

• Multiply magnification of eyepiece by magnification of objective lens

• Eyepiece: 10X

• Objective Lenses: 4X, 10X, 40X

• Example:

• Magnification of eyepiece – 10X

• Magnification of Objective Lens- 4X

• Total magnification= 10 X 4 = 40

Electromagnetic Microscope

• Does not use light to produce image

• High-voltage electrons • Image is projected onto fluorescent screen- digital

• Image produced is much greater than light microscope

Electron Microscope

• Transmission Electron Microscope (TEM): Focusses beam of electrons on thin slice of specimen being studied • Specimen in covered in a chemical

• Detailed observations

• Specimen must be dead

• Scanning Electron Microscope (SEM): Beam of electrons passed over specimen being studied. • Produces a 3-D image of the specimen on the computer

• Can examine living organisms

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Cell Theory

• History of Theory- YouTube

• All living things are made up of one or more cells

• All life functions take place in cells • Cell is the basic unit of life

• All cells are produced from pre-existing cells • Cell division

Characteristics of Living things:

Six characteristics:

1. Made of cells

2. Need energy

3. Grow and develop

4. Respond to the environment

5. Reproduce

6. Adapt to their environment

Note: All living things must have these characteristics

Open System

• Open System: cell must interact with the environment to maintain existence • Cell-to-cell communication

• Reactants

• Receptors

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The Cell:

Viruses

1. Common cold2. Living or non-living?3. No cure.4. No reproduction?

Well how does it spread?

Cell Structures

• Organelles: components of a cell

• Copy Table C2.1 – pg. 267-2

• Cell membrane • Nucleus • Cytoplasm • Chloroplasts • Vacuoles • Endoplasmic Reticulum

• SER• RER• Ribosomes • Lysosomes • Golgi Apparatus • Mitochondria

Plant vs. Animal Cells Cell Membrane

• Cell Membrane: Semipermeable membrane surrounding the cytoplasm of a cell.

• Barrier/wall

• “Skin-like”

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Cytoplasm

• Cytoplasm is the fluid that fills a cell.

Nucleus

• Nucleus: Inside enclosed nuclear membrane (nuclear envelope)

• Contains DNA

• The “brain” of the cell •

Ribosomes

• Ribosomes: protein builders

• Connect one amino acid at a time and build long chains- forming proteins

Endoplasmic Reticulum (ER)

• Endoplasmic Reticulum: functions as a manufacturing and packaging system.

• Rough ER is called rough because it has ribosomesattached to its surface.

• Smooth ER (SER) acts as a storage organelle.

Mitochondria

• Mitochondria: “powerhouse” of the cell.

• Takes in nutrients, breaks them down, and creates energy rich molecules. • Cellular respiration.

Centrioles

• Help divide the cell during cell replication. • Mitosis/Meiosis

• Found near nucleus

• Cannot be seen when the cell is not dividing.

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Golgi Apparatus

• Golgi apparatus: gathers simple molecules and combines them into larger molecules

• Packages information into vesicles• Stores them or sends them out of

the cell.

Vesicles

• Fluid filled cell

• Transport information/material

Vacuole

• Vacuoles: storage bubbles

• They are found in both animal and plant cells • Much larger in plants

• Store food/nutrients .

• Waste products would be sent out of the cell.

Lysosomes

• The purpose of the lysosome is to digest things. They might be used to digest food or break down the cell when it dies.

Cell Wall

• Only found in plant cells

• Outer covering • Made of cellulose

Chloroplast

• Chloroplasts are the food producers of the cell

• Found only in plants

• Convert light energy of the Sun into sugar. • Photosynthesis and it all depends on the little green chlorophyll molecules in

each chloroplast.

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Plant vs. Animal Cell

Animal

• No Cell Wall

• Round• Irregular in shape

• No Chloroplasts

• Many small vacuoles

Plant

• Cell Wall

• Rectangular in shape

• Chloroplasts• Allow for photosynthesis

• Large vacuole

2.2 Transport

• Cell Membrane: protective layer between environment and cell contents • Maintains equilibrium (balance)

• Plasma membrane

• Phospholipid bilayer • Lipid: fat

• Phosphate

Membranes

• Semi-permeable: passage determined by size of molecule

• Selectively permeable: essential nutrients/molecules pass through membrane• Maintain equilibrium

Particle Model of Matter

• Particle Model of Matter: 1. All matter is made up of particles

1. Different substances different size/composition

2. Particles are constantly moving/vibrating

3. Particles attracted to one another or are bonded together

4. Particle s have spaced between them1. Vary – solid, liquid, gas

Diffusion

• Diffusion: passive/natural movement of particles from an area of high concentration to an area of low concentration

• Rate of Diffusion: can increase by adding energy- increasing particle movement• Ex. Stirring, heating

Diffusion

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Concentration Gradient

• Concentration Gradient: determines direction water or solutes will move • Cell membrane acts as barrier/gate keeper

• Equilibrium: balance

• Selectively permeable: cell membrane allows certain molecules/ions to pass through by means of active/passive transport• Semi- permeable

Concentration Gradient

1. Must involve different concentrations

2. Drives diffusion and osmosis

3. Different molecules/ions move along their concentration gradient independently of each other

4. In cells, different concentrations may be separated by a membrane

5. Involve molecules or ions of single type

Osmosis

• Osmosis: water/solvent pass through semipermeable membrane from high to low concentration - equalizing concentrations on each side of membrane.

Osmosis

Tonicity

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Active Transport

• Active Transport: movement of ions/molecules across cell membrane into region of higher concentration• Assisted by enzymes

• Requires energy

Facilitated Diffusion

• Facilitated Diffusion: response to concentration gradient facilitated by protein

• Channel proteins: pores that allow small water-soluble particles to move across the cell membrane

• Carrier Proteins: attach to large molecule unable to diffuse across membrane • Changes shape and carries molecule across membrane

Endocytosis

• Endocytosis: vesicle forms around particle and cell membrane pinches off around it so vesicle is inside the cell • Active Transport

Exocytosis

• Exocytosis: Vesicle with particles move and fuse to the plasma membrane. Vesicles ruptures releasing contents into the surroundings• Transport

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Check and Reflect

3.0 Multicellular

• Multicellular: living system made of many parts

• Multi- multiple (many cells)

• Cell – Tissue – Organ – Organ System

Plant Structure

• Organ Systems-

• Shoot System: • Stem • Leaves • Buds • Flowers• Fruits • Tubers

• Root System: • Roots

• Aerial roots (above ground roots)

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Cell Division

• Meristem: plant tissue- tips of roots and shoots• Area of cell division – new cells

• Mitosis

Epidermis

• Epidermis/Dermal Tissue: outer layer of cells • Covers herbaceous plants

• Herbaceous: non-woody

• Cuticle: Leaves and stem secrete waxy substance- outercoat • Resists attack/reduce water loss

Ground Tissue

• Ground Tissue: majority of plant• Layer beneath epidermis

• Loosely packed tissue • Allow for gas exchange

• Provides strength/support

• Roots- food/water transport

• Location of Photosynthesis

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Vascular Tissue

• Vascular Tissue: responsible for transports • Nutrients

• Water

• Xylem: moves water and dissolved minerals from roots, up stem, to the leaves

• Phloem: transports sucrose and other dissolved sugars from leaves to other parts of plant

• Vascular Plants: Crash Course

Specialized Cells

• Root Hairs: increase surface area • Allow for water absorption

• Cuticle: wax to prevent water loss

Stomata

• Gas is exchanged through holes in the epidermis of the leaf called a stoma (singular) or stomata (plural).

• Two sausage-like guard cells in the epidermis lie tightly in parallel over the stoma and can open and close the entrance to the pore when needed

• Stomata open to allow CO2 in for photosynthesis

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Check and Reflect

• Pg. 302 #’s 1-3

Leaf

• Chloroplast: cell (plastid) that contains chlorophyll and in which photosynthesis takes place.

• Photosynthesis: process using carbon dioxide, solar energy, and water to produce sugar (glucose) and oxygen. • Photo- light

• Synthesis- to make

Photosynthesis

Photosynthesis

• A process that converts solar energy into chemical energy

• Meaning: ‘Light” and “to make or build”.

• Chemical Formula:

• Solar Energy + Carbon Dioxide + Water → Glucose + Oxygen

Chloroplasts• Clusters of CHLOROPHYLL

are found in plant organelles called CHLOROPLASTS

• yep… they’re green!

• Site of photosynthesis

• Structure of a chloroplast:

• Outer & Inner MembraneThylakoid Membranes (Discs): contain chlorophyll

Grana: Stacks of Thylakoid Discs

Stroma: gel-like enzyme-rich substance filling the chloroplast

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Leaf structure• Most chloroplasts are found in a layer of cells at

the TOP of a leaf

The PALISADE MESOPHYLL LAYER

• The sun first passes through the waxy cuticle, then through the upper epidermis, then finally to the Palisade Mesophyll layer

Check Your Understanding:

1. What is chlorophyll?

2. Identify the regions of the chloroplast indicated on this diagram. Describe what happens in C.

3. Describe the major function of photosynthetic pigments.

Cellular Respiration

• Cellular Respiration: set of reactions to obtain energy

• Process occurs in the mitochondria

• Glucose + Oxygen → Carbon Dioxide + Water + Energy (ATP)

• Chemical Formula:

ATP

• ATP: Adenosine triphosphate

• Energy • Currency in the cell

• Produced in mitochondria • Cellular Respiration

• Breakdown of glucose

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Check and Reflect

• Pg. 308 #’s 1, 2, 5.

Transpiration

• Transpiration – the plant process that pulls the water up from the roots.

1st - evaporation of water from the surface of the leaves.

2nd – evaporated water pulls water inside stem up to the leaves.

3rd – water is continuously pulled which brings water into the roots.

Transpiration

Transpiration

• Transpiration: water movement through the plant • loss of water vapor from plants to the atmosphere through stomata

• Stomata: holes in the undersides of leaves • open to allow carbon dioxide into leaf tissues

• During the daytime hours (sunlight), stomata open to allow CO2 to enter the leaf• water vapour is evaporating

• Water moves up xylem tubes against gravity from the roots

A Process for Moving Water Up from the Roots

• Plants move water from the roots up to the leaves through several processes.

Capillary Action

• Two processes help move the water up the narrow tube.

• Cohesion – water is attracted to other water particles.• Copartner/copilot

• Adhesion – water is attracted to the walls of the narrow tube in stem.• Adhering

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Root Pressure

• Root Pressure

• Dissolved minerals in roots create high solute concentration • Process of osmosis

• Water moves high to low

• Water drawn into cells creating pressure forcing fluid up xylem

• High pressure in roots to low pressure in leaves

Tension

• Evaporation of water through leaves creates tension/transpiration pull

• Tension: force

• As water evaporates this creates pull on adjacent water molecules • Water that does not evaporate is used for photosynthesis

Tonicity in Plants

• Tonicity: measure of osmotic pressure

• Changes effect rate of osmosis

• Plasmolysis: contraction of plant cell due to water loss • Water contained in vacuole leaves cell – solute concentration outside the cell

is high • Leaf appears wilted

Sugar Flow

• Source: Where photosynthesis takes place- sugars formed

• Sink: Where sugar is stored • Sugars actively transported

• Sugars move through phloem

Check and Reflect

• Pg. 322 #’s 1-4

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