Science 10 - Biology- Part 1

First half of biology content for science 10. Organized based on what made sense to my brain at 3:56AM on the fifth of january. Square brackets indicate my mnemonic tricks.

Microscope Development - Janssen

Microscope Development - Janssen

Earliest microscope model, made of 2 eyeglass lenses

Microscope Development - Robert Hooke

Observed cork under a microscope, coined term “Cells”

Microscope Development - Anton van Leewenhoek

First observation of single celled organisms (animalcules) using paddle microscope (his innovated microscope)

Light Microscope

Can be simple (1 lens) or compound (2 lens). Uses curved lenses to magnify an image

Confocal Microscope

Uses laser to concentrate light on a specimen for an image, images can later be used for 3D image of specimen. Can be used with fluorescence microscopy for detailed imagery. Can be used to view live specimen or without staining.

Electron Microscopes

Use concentrated electrons to “illuminate” an image. Images have very high resolutions

Transmission Electron Microscope (TEM)

Electron microscope where electrons are passed through thin sample of specimen

Scanning Electron Microscope (SEM)

Electron microscope where specimen is coated in electron dense material (ie gold) and electrons reflect off the surface of the specimen to create 3D image.

Magnification

How large an image is in comparison to the actual thing (Found using objective lens +ocular lens)

Contrast

Amount of light absorbed by object in comparison to its surroundings. Involves staining the cells, affected by amount of light

Resolution

How clear the image is

Field of View (FoV)

Diameter of the area you can see using a microscope, typically measured in ɥm (micrometers)

Fit Number (Fit#)

Number of specimen that would fit across *can vary depending if horizontal or vertical*

Actual Size (AS)

The actual size of the specimen. Calculated by FoV/Fit #

Drawing Magnification (Scale)

Scale to which the specimen has been drawn. Calculated by Drawing Size/AS

Spontaneous Generation

Theory that life could be created on its own. Believed by Aristotle and Needham

Miasma Theory

Theory that diseases (ex. Plague) were caused by “bad air”

Spont. Gen. - Aristotle [ARNS+P]

Believed in Spont. Gen.

- Left out meat and maggots appeared

Spont. Gen. - Francisco Redi [ARNS+P, Maggot Meat Man]

Tried to disprove Spont. Gen.

- 3 jars of meat with different coverings, maggots only appeared on uncovered meat

Spont. Gen. - John Needham [ARNS+P]

Believed in Spont. Gen.

- Boiled chicken broth, exposed it to air, then sealed it. Bacteria appeared in the broth despite boiling

Spont. Gen. - Lazzaro Spallanzani [ARNS+P, Better Needham]

Tried to disprove Spont. Gen. Believed micro-organisms in the air were responsible for growth

- Repeated Needham’s experiment with modification of having broth sealed the entire process. No bacteria appeared

Spont. Gen. - Loui Pasteur [ARNS+P, Pasteurized Eggs]

Disproved Spont. Gen.

- Boiled broth in swan neck container (for exposure to air)

→ proved air contact was not the problem, but bacteria in the air (bacteria didn’t have enough momentum to get through swan neck)

- Concluded life needs pre-existing life

Modern Cell Theory

1. All living things are made up of one or more cells

2. Cells are the smallest unit of life

3. All cells are produced from pre-existing cells

Cell Theory History - Aristotle

Created classification system for animals based on observation

Cell Theory History - Robert Brown

Identified nucleus

Cell Theory History - Schleiden

Proposed nucleus was responsible for cell control. Defined cells as basic unit of life in plants. With Schwann, proposed basic cell theory

Cell Theory History - Schwann

Defined cells as basic unit of life in animals. Identified similarities between plant and animal cells. With Schleiden, proposed basic cell theory

Cell Theory History - Schleiden/Schwann Theory

1. All animal and plant cells are made of cells

2. Cells are the basic unit of life in all organisms

Cell Theory History - Virchow

Added cell reproduction to cell theory (All cells come from pre-existing cells)

Requirements of Living Things

1. Intake of nutrients

2. Production of waste

3. Reproduction

4. Movement

5. Growth

6. Response to stimuli

7. Exchange of gases

Prokaryotic Cells

Cells that do not have a defined nucleus or membrane-bound organelles (distinct organelles. First forms of life before evolution, have circular DNA

Eukaryotic Cells

Cells that have a defined nucleus (true nucleus) as well as membrane-bound organelles. (ie. plant and animal cells). Can have double-membrane-bound organelles (mitochondria, chloroplasts), linear DNA

Cell Structure/Organelles - Chemical Composition

1. Carbohydrates - sugar, starches, cellulose

2. Lipids - fats, oils

3. Proteins - muscle fiber, enzymes

4. Nucleic Acids - DNA, RNA

5. Trace Elements - Zinc, Magnesium (Kind of irrelevant)

Permeable

Allowing entry (into cell)

Semi-Permeable [Bouncer]

Selectively allowing entry (into cell). Decided based on

1. Size (Smaller size = more permeable)

2. Charge - positive or negative (uncharged = more permeable)

3. Solubility in lipids

Impermeable

Not allowing entry (into cell)

Cell Structure/Organelles - Cell Membrane

Separates interior of cell form exterior. Regulates what enters/exits cell (semi-permeable) - create balance inside of the cell. Made of phospholipid bilayer

Cell Structure/Organelles - Phospholipid Bilayer

2 layers of phospholipids - heads on outside, tails on inside (phospholipid: molecule with hydrophilic head, hydrophobic tails). Represented by the fluid mosaic model. An example is the cell membrane

Cell Structure/Organelles - Fluid Mosaic Model

Phospholipid bilayer that has other things (ie protiens) imbedded in it. Representation of cell membrane

Cell Structure/Organelles - Nucleus

Controls cell activity, stores DNA, regulates gene expression

Cell Structure/Organelles - Nuclear Envelope

Surrounds nucleus, allows through transport of materials through pores. Made of phospholipid bilayer

Cell Structure/Organelles - Cytoplasm

Jelly-like substance responsible for keeping organelles in place. Contains cell’s required nutrients

Cell Structure/Organelles - Rough Endoplasmic Reticulum (RER)

Processes proteins and then ships them to SER (Internal delivery system). Has ribosomes attached, connected to nuclear envelope.

Cell Structure/Organelles - Smooth Endoplasmic Reticulum (SER)

Process/synthesize lipids/lipid-containing molecules (ie. phospholipids). Found near nucleus

Cell Structure/Organelles - Ribosomes

Synthesize proteins in the cell. Found attached to RER or free-floating in cytoplasm. Made of RNA

Cell Structure/Organelles - Golgi Apparatus

Sorts received products from RER/SER + packages those products into vesicles. Can package, modify, and transport materials to inside/outside of cell. Shaped like pancakes, found away from nucleus.

Cell Structure/Organelles - Vesicles

Membrane-bound organelle used for transport and storage of materials (ie nutrients). Used in exocytosis and endocytosis. Found throughout cell.

Cell Structure/Organelles - Mitochondria

Double-membrane-bound organelle where cellular respiration occurs (conversion of chemical energy into sugars and ATP). Multiple per cell

Cell Structure/Organelles - Cytoskeleton

Network of protein fibers throughout the cell. Provides structure/shape to cells and pathways for organelles to travel on.

Cell Structure/Organelles - Centrioles

Develop spindle fibers during cell division/move copies of DNA. Shaped like tubes and found throughout cell, only found in animal cells.

Cell Structure/Organelles - Lysosomes

Specialized vesicle that acts as a purifier in the cell (digestion of certain tissues, destruction of damaged organelles, defense against bacteria). Only found in animal cells

Cell Structure/Organelles - Central Vacuole

Large vesicle that stores water and nutrients, also contains enzymes to break down waste/macromolecules. Contribute to turgor pressure (how rigid a cell is). Found only in plant cells

Cell Structure/Organelles - Chloroplasts

Where light energy is stored/captured as high-energy molecules (ie. glucose). Contains chlorophyll and where photosynthesis occurs. Only found in plant cells

Cell Structure/Organelles - Cell Wall

Rigid organelle on the outside of plant cells that provides structure, shape, and protection for the cell. Composed of proteins or carbohydrates, only found in plant cells.

Cellular Respiration

Conversion of glucose and oxygen to carbon dioxide, water, and ATP.

Photosynthesis

Conversion of carbon dioxide and water with light energy (ie sun) to produce glucose and oxygen

Dynamic Equilibrium

A state of equilibrium where molecules still are in continuous motion despite uniformity

Cell Transport - Types

1. Passive

2. Active

Cell Transport - Concentration Gradient

A difference in concentration between one side of a membrane and the other

Cell Transport - Passive Transport (PT)

Type of cell transport that does not require energy (ATP). Movement of molecules from areas of high concentration to low concentration.

1. Diffusion

2. Osmosis

3. Facilitated Diffusion

Cell Transport (PT) - Diffusion

Natural movement of particles from areas of high to low concentration until concentration is uniform throughout (Dynamic Equilibrium). (ie. breathing)

Cell Transport (PT) - Diffusion Rate Factors

1. Molecule size - large molecule = lower rate

2. Polarity - polar molecule = lower rate

3. Ion charge - most charged molecules/ions cannot cross

4. Temperature - lower temperature = lower rate

Cell Transport (PT) - Osmosis

Diffusion of water across semi-permeable membrane from high to low concentration

Tonicity

Comparisons of concentrations (in ratios), can compare cells or solutions. 3 kinds:

1. Hypotonic (cell or solution)

2. Hypertonic (cell or solution)

3. Isotonic (cell or solution)

Hypotonic Solution

(Hypo = losing water) Solution has more water to solute than cell. Water will flow into cell, causing cell to swell - may burst (lysis) - if plant cell, turgor pressure will develop. (Opposite applies for cell)

Lysis

When a cell bursts

Hypertonic Solution

(Hyper = gaining water) Solution has less water to solute than cell. Water will flow out of cell, causing cell to shrink. (Opposite applies for cell)

Isotonic Solution

(Iso = equal water) Water to solute ratio of solution is equal to that of cell.

Cell Transport (PT) - Facilitated Diffusion

Transport of molecules across a membrane along the concentration gradient by means of a protein

1. Carrier protein (binding)

2. Channel protein (not binding)

Facilitated Diffusion - Carrier Protein

A protein that binds to the molecule that is being transported through the membrane

- Changes shape to move the molecule, then back to original shape

- Used for larger molecules

Facilitated Diffusion - Channel Protein

A protein that creates pores for water-soluble molecules to go through, along the concentration gradient

- Acts as a slide in/out of cell

Cell Transport - Active Transport (AT)

Movement of molecules against the concentration gradient. Require ATP.

1. Protein pump

2. Endocytosis

3. Exocytosis

Cell Transport (AT) - Protein Pump

A protein that moves materials against the concentration gradient with ATP

Cell Transport (AT) - Endocytosis

The formation of a vesicle to bring in molecules from the outside of the cell. Used for bulk transports, a type of membrane-assisted transport. (Creation of a vesicle)

Cell Transport (AT) - Exocytosis

A vesicle merging with the cell membrane in order to release molecules outside of the cell. Used for bulk transports, a type of membrane-assisted transport. (Vesicle merges with cell membrane)

Membrane-assisted Transport

A method of transport for bulk transports that cannot cross a carrier or channel protein. Require ATP and membranes

Cell Interaction - Size

Smaller things have a larger SA:V ratio, allowing it to interact with the environment better.