Bio Lab Exam #1

Iris Diaphragm

controls the amount of light and together with the condenser affects the sharpness of the image

Stage

holds the slide

Condenser

concentrates the light on the specimen

Calculate Chi-Square (x2)

(observed-expected)2/expected

Kingdom Fungi

Rhizopu

What steps are included in a good experiment?

- Testability and Repeatability - Proper Controls - One Variable - Sample Size - Correlation and Causation

Things you should do with a microscope

-plug the microscope in and set the voltage regulator to about half its maximum intensity -adjust the interpupillary distance and the diopter ring -turn on the light and adjust the diaphragm -be sure the smallest (4X) objective is in place before inserting a slide. Raise the stage all the way while looking from the side -slowly lower the stage with the coarse focus knob. Once in focus, use only the fine focus knob. Coarse focus knob is never to be used with the higher power objectives in place

Things you should NOT do with a microscope

-use the coarse adjustment knob unless the 4X objective is in place -change objective lenses by rotating them -decrease the distance between the lens and the slide when focusing - use anything except lens paper to clean lenses-remove eyepieces-touch lenses with your fingers -remove a slide with the high or medium power objective in the down position-move the mechanical stage with your fingers

Calvin benson cycle (light independent reaction)

1. 6 CO2 molecules enter the cylce and are used to make one glucose 2. The Calvin-benson cycle requires ATP and NADPH (from light dependent reactions) to make the glucose

How do you determine if a scientific source is reliable?

1. Gather further information, don't rely on just one report. 2. Understand and define all terms. 3. Question the methods used to derive the data. 4. Question the conclusions (are they based on the data collected) 5. Uncover any bias 6. Are the results consistent with other known information. 7. DON'T expect all the answers or complete information

Lugol's Test

A change to blue or black indicates the presence of POLYSACCHARIDES. POSITIVE RESULTS: Starch, Potato Slice, Starch+A.A. NEGATIVE RESULTS: Water, Glucose, Onion Juice, Glucose +A.A, Milk

How did we test the different antibiotics and antiseptics?

1. Use a swab to gather bacteria from culture tube. 2. Wipe the swab onto the agar in the petri dish, swab the entire plate. 3. Repeat these steps with your 2nd petri dish 4. Place 4 antibiotic discs on petri dish 1 5. Choose 4 antiseptics (lysol,crest) for petri dish 2 and write names on the bottom of the dish 6. Swab a common surface and place in petri dish 3 7. Incubate upside down

Dialysis Experiment

3 bags put in a beaker of distilled water for 60 min. Bag 1 10ml of distilled water, bag 2 10ml 10% sucrose solution, bag 3 10ml 20% sucrose solution. Weight before and after. All weight increased, but 20% sucrose the most. 20% solution was hypertonic so the hypotonic water went into the bag.

Equation for Photosynthesis

6 CO2 + 12 H2O *LIGHT* C6H12O6 + 6O2 Photosynthesis has 2 parts: 1)light dependent reaction, 2) light independent reaction Light dependent reactions convert solar energy to chemical energy (stored in ATP and NADPH) ATP and NADPH made during the light dependent reactions are used to make organic molecules (like glucose) from CO2 during the light-independent reactions.

What is the difference between hypothesis and scientific theory?

A HYPOTHESIS is formed to explain observations in the natural world. The hypothesis may then be tested using the steps in the scientific method. A THEORY is a broad and comprehensive statement about the world that is supported by the accumulation of a great deal of verifiable evidence.

Kingdom Protista

Amoeba and Volvox

Gram Negative

Bacteria that stain pink to red and more susceptible to streptomycin. Gram- are rods, coccus, or spiral. Example from lab E.coli

Gram Positive

Bacteria that stain purple to black and are more susceptible to penicillin. Gram+ are either rod or cocci (round) Example from lab S.epidermidis

Chemiosmosis

Chemiosmosis is the diffusion of hydrogen ions (protons) across the biological membrane via the ATP synthase (a transport protein) due to a proton gradient that forms on the other side of the membrane. The proton gradient forms when the hydrogen ions accumulate as they are forcibly moved to the other side of the membrane by carrier proteins while the electrons pass through the electron transport chain in the membrane. Since more hydrogen ions are on the other side they tend to move back across the membrane via the ATP synthase. As they flow through energy is released which is then used to convert ADP to ATP (by a process called PHOSPHORYLATION

Potato experiment

ENZYME: catalase SUBSTRATE: hydrogen peroxide VARIABLE TESTED FOR: Changing the pH of the solution BASIC RESULT: Activity is highest at lower pH

Jello experiment

ENZYME: pineapple SUBSTRATE: jello VARIABLE TESTED FOR: did the jello set? BASIC RESULT: Only one that set was the control, the boiled pineapple had been denatured

Rennin Experiment

ENZYME: rennin SUBSTRATE: milk VARIABLE TESTED FOR: temperature BASIC RESULT: Optimum temp is 37 degrees celsius

Urea Experiment

ENZYME: urease SUBSTRATE: ammonia VARIABLE TESTED FOR: time for color change to occur BASIC RESULT: The more enzymes added, the faster the solution changed from acidic to basic

Determine the control: Researchers set up an experiment to determine the amounts of different kinds of fat in the adipose tissue of 79 patients who had experienced heart attacks. These amounts were compared with the data for 167 patients who had not experienced a heart attack but were similar to the first group in most repeats.

EXPERIMENTAL GROUP: patients who had heart attacks CONTROL GROUP: patient who had not had heart attacks THEY ONLY DIFFER IN THE OCCURRENCE OF THE HEART ATTACK

Kingdom Plantae

Elodea leaf cells

Plasmolysis in carrots

Filled 2 beakers, 1 with water and 1 with NaCl solution, placed carrot sticks inside. Carrots in the water remained stiff were hypotonic and remained stiff. Carrots in the NaCl solution became limp, hypertonic.

Using the chi-square Values chart, determine if a hypothesis should be accepted or rejected?

Find 5% (p=.05) and if the chi-square is LESS THAN that number you ACCEPT your hypothesis because it will deviate on 5% of the time, but if it is GREATER THAN that number you would REJECT your hypothesis because it could deviate more than 5% of the time.

Effect of Solute concentration on Osmosis

If the solute concentration is increased then the rate of osmosis will slow down

Degrees of Freedom

Number of variables - 1

What is the difference between a positive control and a negative control?

POSITIVE CONTROL expects a positive resut, for example adding Benedicts reagent to a solution known to contain sugar like glucose, it changes color. NEGATIVE CONTROL expects a negative result, for example adding the reagant to a solution known to NOT contain sugars like distilled water to ensure the reagent is still good and making sure the water does not change colors.

Plasmolysis in Elodea

Placed elodea cells under microscope and viewed, then added hypertonic solution (5-10% NaCl) The chloroplasts clumped together in the center when the solution was added(hypertonic). Then added water again (deplasmolysis) until chloroplasts return to normal lining up along the cell wall (hypotonic).

Light Dependent Reactions (light dependent reaction)

Take place in the thylakoid membrane of chloroplast 1. Electrons used are generated by splitting water 2. When water is split, O2 is released 3. Solar energy is gathered by the pigments 4. As electrons travel down an electron transport chain, the energy released is used to make ATP (by CHEMIOSMOSIS) 5. The final electron acceptor is NADP+, then NADPH is formed.

Lipase Test

Test for LIPIDS Note the color of the tubes after 1 hour, added 0.1 N HCI drop into the tube until the color changes pink. TESTING FOR: tubes that showed a pH after 1 hour at 37 C and why? POSITIVE RESULTS: Tube 2 that only had lipase in it NEGATIVE RESULTS: Tube 3, which had lipase, and bile salts

Ninhydrin

Testing for amino acids. If amino acids are present the spot on the filter paper will turn purple. POSITIVE RESULTS: Amino 1&2 NEGATIVE RESULTS: Water

Grease Spot Test

Tests for the presence of LIPIDS POSITIVE RESULTS: Oil (stained) NEGATIVE RESULTS: Water (disappeared)

Biuret's Agent

Tests for the presence of protein, peptide bonds. POSITIVE RESULTS: egg albumin NEGATIVE RESULTS: water, starch, glucose, amino acid

Phosphorylation

The creation of a phosphate derivative of an organic molecule. This is usually achieved by transferring a phosphate group from a TP. The process of adding a phosphate to a molecule, and occurs in RESPIRATION and PHOTOSYNTHESIS

How do various objectives influence the diameter of the microscope field?

The diameter of the field decreases as the magnification increases. The decrease is the same factor as the increase. Example changing from 4X to 10X objective is an increase of 2.5 (4x2.5=10) so there is a decrease in diameter of 2.5

Benedict's Test

The presence of a yellow, orange, red, brown, or blue/green precipitate indicates the presence of a MONOSACCHARIDE. The darker the color the more monosaccharides are present. POSITIVE RESULTS: Starch, Glucose, Prune Juice, Potato Slice, Glucose+A.A, Milk NEGATIVE RESULTS: Water, Starch+A.A

Effect of Molecule size on Diffusion

The rate of diffusion of large molecules is slower than that of small molecules.

Plasmolysis in Red Onion Cells

Took a piece of red onion epidermis and placed under microscope with a drop of water. Observed the vacuole and then added NaCl solution (hypertonic) which caused the water to rush out of the vacuole and it shrunk. When we added water (hypotonic) back to the cell it returned to normal.

Diopter ring

allows you to adjust the focus of the left ocular lens independently of the right lens

Voltage Regulator

allows you to adjust the intensity of the light source

Revolving nosepiece

allows you to change objective lenses

Celsius to Fahrenheit Fahrenheit to Celsius

c=5/9(f-32) f=9/5(c+32)

Objective lenses

magnifies the image

Ocular lenses

magnifies the image

Coarse focus knob

makes large adjustments in focus

Fine focus knob

makes small adjustments in focus

Mechanical stage adjustment knobs

moves the slide on the stage