BIO Lab #1

Scientific Method

Make Observations, Questioning, Form Hypothesis, Test Hypothesis, Draw Conclusions

Make Observations

Collect info. Data must be verified by another person

Questioning

What is the cause?

Looking at cause and effect

Form Hypothesis

Tentative explanation, uses inductive reasoning

Test Hypothesis

Conducting the controlled experiment. Uses deductive reasoning. Analyze the data using statistics

Draw Conclusions

Accept or reject hypothesis, revise hypothesis. Hypothesis can't be proven true but can be proven false

Control Group

Controlling the conditions of the experiment

Control Group

Must remain constant throughout the experiment

Experimental Group

Receives the independent variable

Metric System

To convert between units, just move the decimal over the appropriate amount.

Pipette

Measures Volume

Metric Ruler

Measures Length

Beaker

Measures Volume

Triple beam balance

Measures Mass

Graduated Cylinder

Measures Volume

Erlenmeyer Flask

Measures Volume

What is the meniscus in a graduated cylinder?

The curved surface of the liquid

How to read a metric ruler

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What are the different types of microscopes? Which type do we use in lab?

\-Compound Light Microscope (We use this one in lab)

\-Stereomicroscope

\-Teaching scope (Team scope)

\-Phase contrast microscope

\-Transmission electron microscope

\-Scanning electron microscope

Ocular

Lens nearest to eye

Body Tube

Keep ocular and objective lenses at proper distances from each other

Nosepiece

Permits interchange of scanning, low, and high power objectives

Pointer

Found in the ocular, can be moved by turning the black eyepiece

Arm

Supports the body tube and adjustment knobs

Objectives

Contains lenses of various magnifications

Coarse Adjustment

Changes the distance between the slide and objective to focus an image

Fine Adjustment

Permits exact focusing

Base

Bears the weight of the microscope

Stage

Supports slide

Stage Clips

Holds slide steady

Iris Diaphragm

Regulates the amount of light going through the specimen

Illuminator

\n Provides the light source

What is meant by field of view?

The circular field you see when you look through the ocular

Depth of focus

The thickness of an object that is all in sharp focus at the same time

How do you calculate the total magnification?

Magnification of the objective multiplied by the magnification of the ocular (10) equals total magnification.

What is the proper way to use (focus) the microscope?

1. Use the coarse adjustment knob on scanning power
2. Use the fine adjustment to obtain a sharp focus
3. Turn the nosepiece to low power, use coarse and fine adjustment
4. Repeat the same on high power

How does magnification affect working distance and light intensity?

Increasing the magnification decreases both the working distance and light intensity

wet mount

Slides used to look at tissues or cells of living organisms

Test used for detecting presence of reducing sugars, and color change results from a positive test

Benedict's Reagent + Heat for 2 minutes

Positive test - Yellow

Starch

Iodine

Positive test - Blue/Black

Lipids

Add vegetable oil to a test tube of water (emulsion)

Add Sudan and mix

Add liquid detergent

Reagent: Sudan

Positive test - Red

Proteins

Biuret

Positive test - Purple

Name the monomers of starch, lipids, and proteins

Starch - Glucose

Lipids - Fatty Acids and Glycerol

Proteins - Animo Acids

Monomer

A molecule that can be bonded with an identical molecule to form a polymer

Polymer

\n A chain of monomers

Dehydration Synthesis

\n Bonding of 2 monomers to form a polymer while losing water

Hydrolysis

Splitting of a polymer into 2 monomers while gaining water

reducing sugar

Monosaccharides; has the ability to add electrons to reduce other molecules

function of detergent

Functions as an emulsifier

What is an emulsion? emulsifier

Emulsion - The mixture of two liquids, each insoluble to the other.

Emulsifier - A substance that activates the emulsion (Liquid detergent)

Plasma Membrane

Structure - Composed of proteins and phospholipids molecules

Function - Provides form to the cell and controls passage of materials in and out of the cell.

Cell Wall

Structure - Cellulose fibrils

Function - Provides support and rigidity to the plant cell

Cytoplasm

Structure - Fluid to jelly like substance

Function - Suspending medium of organelles

Endoplasmic Reticulum

Structure - Interconnecting hollow channels

Function - Supporting framework of cell; cell transport

Ribosomes

Structure - Granules of nucleic acids

Function - Protein synthesis

Mitochondria

Structure - Double-layered sacs with cristae

Function - Production of ATP

Golgi Apparatus

Structure - Flattened sacs with vacuoles

Function - Synthesize carbohydrates and package molecules for secretion

Lysosomes

Structure - Membrane-surrounded sacs of enzymes

Function - Digest foreign molecules and worn cells

Centrosome

Structure - Mass of two rod-like centrioles

Function - Organizes spindle fibers and assist mitosis

Vacuoles

Structure - Membraneous sacs

Function - Stores and excretes substances within the cytoplasm

Fibrils and Microtubules

Structure - Protein strands

Function - Supports cytoplasm and transports materials

Cilia and Flagella

Structure - Cytoplasmic extensions from cell

Function - Movement of particles along cell surface or move cell

Nucleus

Structure - Nuclear membrane, nucleolus, and chromatin (DNA)

Function - Direct cell activity; forms ribosomes

Chloroplasts

Structure - Inner (grana) membrane within outer membrane

Function - Photosynthesis

Hypotonic

\n Occurs when the osmotic pressure inside the cell is greater than the osmotic pressure outside the cell (Cell Expands)

Isotonic

Occurs when the osmotic pressure inside the cell is identical to the osmotic pressure outside the cell (Normal Cell)

Hypertonic

Occurs when the osmotic pressure inside the cell is less than the osmotic pressure outside the cell (Cell Shrinks)

Crenation

Shrinkage of a cell as a result of losing water

Hemolysis

The bursting of a cell as a result of gaining too much water

Turgor Pressure

The pressure exerted on the cell membrane as a result of water entering the cell

Plasmolysis

Contraction of the protoplast of a plant cell as a result of loss of water from the cell

Flaccid

The cell membrane is not under pressure; is being shrunk

Interphase

the beginning cell

Prophase

the first step to splitting a cell

Metaphase

the second step where a wall is visible

Anaphase

third step where separation can be seen

Telophase

final step where cell is still connected but with a cell wall between

Identify chromosomes

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Identify the cytoplasm

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Identify the nucleus

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Identify the nucleolus

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Identify the cell wall

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Mitosis

a process where a single cell divides into two identical daughter cells

Meiosis

a process where a single cell divides twice to produce four cells containing half the original amount of genetic information.

Enzymes & how they work

Proteins that speed up chemical reactions; lower the activation energy and bind to a specific molecule

Denature

take away or alter the natural qualities of

What effect do temperature and pH have on the rate of reaction?

Raising temperature generally speeds up a reaction, and lowering temperature slows down a reaction; Changing the pH outside of the optimal range will slow enzyme activity

What did the experiment involving a mixture of milk and rennin incubated at different temperatures illustrate?

how temperature effects enzymes: the rate of reaction and color

Rennin

an enzyme secreted into the stomach of unweaned mammals, and in some lower animals and plants, causing the curdling of milk

What’s the breakdown of hydrogen peroxide involving catalase? What were the bubbles?

A catalase detoxifies hydrogen peroxide by breaking it down into water and oxygen gas; the bubbles resulting from production of oxygen gas clearly indicate a catalase positive result

What effect did macerating (mashing) the potatoes have on the rate of reaction? Why?

It sped the process up because the cells were already destroyed

Gene

Structural and functional subunits that contain coded information for making a specific protein

Trait

individual’s observable physical characteristics

Allele

different forms of a gene that occupy the same position on homologous chromosomes

Heterozygous

an individual has two different alleles for a given trait

Homozygous

an individual has two alike alleles for a given trait

Genotype

the genetic makeup of an individual

Phenotype

a specific trait (i.e. brown eyes for eye color)

Dominant

the stronger allele when one allele may completely mask the presence of the other one

Recessive

the weaker allele when one allele may completely mask the presence of the other one