Biology_lab.txt

variable thats counted or measured or observed

variable thats being manipulated

other independent variables, that stay consistent

value set for the indepependent variable

same procedure repeated

benchmark, independent is held or omitted

• All values of the same kind should be read down a column
• Omit information and results
• Headings should include units of measurement
• Tables numbered consecutively throughout labs
• Title located at top of table
• Capatalize first and important words (not a, an, the)
• When refering to table (Table 1.4) not "see the results in Table 1.4)

• Use graph paper and ruler to plot accurately
• Independent variable on x-axis (horizontal)
• Dependent variable on y-axis (vertical)
• Use appropriate numerical range
• Start with zero, to save space may use double tick marks between 0 and lowest #
• Label axes to indicate variable, and units of measurement
• Include legend with colors if needed
• Choice bar/line graph depending onnature of variable beign graphed
• Title below graph and numbered consecutively
• Only first word capital and end with period

• show changes in the quanity of chosen variable
• emphasize rise and fall
• use to present continuous quanitive data
• changes in dep. variable, weight, or measured over time

• vertical bars are drawn down to horizontal axis
• used for data to represent seperate or discontinuous groups or nonnumerical categories
• emphsize discrete differences between the groups
• when values on x axis are numerical but grouped together called histograms

• minimum of two magnifying lenses
• binocular or monocular microscopes

supports the two sets of magnifying lenses

• the lens in the eyepiece
• typically has a magnification of 10x

• distance between the eyepieces
• can be adjusted to suit your eyes

• is the circle of light that one sees in the microscope
• has a pointer to point to an object

• the three lenses on the revolving masterpiece
• shortest to longesxt lense; 4x, 10x, 40x
• clean lenses each time to avoid blurring or fogging of image
• always use lense paper

4x

10x

40x

supports the stage and condenser lens

• used to focus the light from the lamp through the specimen to be viewed
• hieght can be adjusted by an adjustment knob

controls the the width of the circle of light and, therefore, the amount of light passing through the specimen

• if microscope has phase-contrast optics the condenser is housed here
• when set on 0 the normal optical arrangement is in place (called brightfeild microscopy)
• to use phase-contrast, turret settins must correspond to the magnifying power of the objective being used

• supports the specimen to be viewed
• a mechanical stage can be moved right and left and back and fourth

two adjustment knobs for the stage

the slide is secured under stage clips and moved slightly by hand while vieing the slide

• adjustment for the distance between the stage and the objective
• can also use the fine focus adjustment knobs

Acts as a stand for the microscope and houses the lamp

adjusts the intesity of the light that passes through the specimen

• low magnification of 7x to 30x
• for viewing and manipulation relatively large objects
• binocular feature creates the stereoscopic effect
• depth of feild is much greater than with the CM so objects are in 3 dimension
• the light source can be directed down onto as well as up through an object which permits viewing of objects too thick to transmit light

light directed down on the object

light passing through

distance between the specimen and the objective lens

multiply the magnification of the ocular lens by that of the objective lens

to the right

• place a drop of water and your specimen on the slide
• using a disecting needle, slowly lower a coverslip onto the slide
• be careful not to trsap air bubbles in the droplet

Place the coverslip at a 45 degree angle

• with two hands
• one holding the arm
• the other supporting the base

• rotate 4x objective into position
• remove slide from stage
• return phase-contrast condenser to 0 setting
• lower stage completely
• set light to lowest intesity
• turn off
• wrap the cord
• cover with dust jacket

cells swell and membranes burst

cells shrivel and appear bumpy

type of diffusion of water through selectively permeable membrane from region where it is highly concentrated to a region where its concentration is lower

large particles suspended in water in motion

I₂KI tests for presence of starch when it is added to an unknown solution

It was permeable to the glucose but not the starch into the beaker, and the I₂KI got into the tubing because of the size of the molecules

tests for presence of starch by turning purple or black when added to the unknown solution

• when reagent is added to unknown solution, solution is heated, if turns green, orange, or orange-red, a reducing sugar is present
• if no reducing sugar is present the solution remains the color of the Benedict's reagent (blue)

has a greater concentration of solutes that cannot cross the membrane (nonpenetration solutes) than the solution on the other side of the membrane greater osmolarity (solute concentration expressed as molarity)

has a lower conentration of nonpenetrating solutes, or a lower osmolarity, than the solution on the otherside of the membrane

when the two solutions are in equilibrium, the concentration of nonpenetrating solutes being equal on both sides of the membrane, the osmolarities are equal

the net flow of water is from the hypotonic solution to the hypertonic solution, when the solutions are isotonic, there is not net flow of water across the membrane

the cells swell and the membranes burst, or undergo lysis

the cells shrivel and appear bumpy or crenate

• as water moves into the cell and the cell's central vacuole, the cell's protoplast expands
• the cell wall restricts the expansion, resulting in turgor pressure
• a high turgor pressure will prevent further movement of water into the cell

• water moves out of the cell
• the protoplast shrinks and pulls away from the cell wall call plasmolysis
• the cell is then described as plasmolyzed

• proteins
• biological catalysts, compounds that speed up a chemical reaction without being used up or altered in the reaction
• a small amount of enzyme can alter a relatively enormous amount of substrate

• the material with which the catalyst reacts
• modified during the reaction to form a new product

• active site of an enzyme that will bind with the substrate forming the enzyme-substrate complex
• site where catalysis takes place and when complete dissociates into enzyme and product or products

catechol is a phenolic compound found in plant cells and is converted to benzoquinone, a pigment product by catechol oxidase

the extract is to test for the presence of catechol oxidase

• phenylthiourea is the specific inhibitor
• known to combine with the copper in catechol oxidase and inhibits its enzymatic activity

catechol oxidase and amylase

catechol

adding additional substrate (catechol) will not reverse the inhibition if it is a noncompetitive inhibition

enzyme concentration, pH, and temperature

• chemical reactions accelerate as temperature rises, however high temperatures denature the protein
• After conducting an expirement at four different temperatures, in four different test tubes, the results yeilded that between 22 and 37 degrees the reaction time is the quickest, where as it slows down at higher temperatures of 80 degrees

• the inhibitor binds to a part of the enzyme that is not the active site, in so doing it changes the nature of the enzyme so that its catalytic properties are lost
• 1) either the NI itself physically blocks the acces to the active site
• 2) it causes a conformational change in the protein, thus inactivating the active site
• the inhibitor can become unbound, reversing the inhibition
• unlike competitive inhibition, adding additional substrate will not reverse the inhibition

• when a molecule structurally similiar to the substrate for a particular reaction competes for a position at the active site on the enzyme
• tieing up the enzyme so that it is not available to the substrate
• competitive inhibition can be reversed if the concentration of substrate is raised to sufficiently high levels while the concentration of the inhibitor is held constant

capable of utilizing only organic materials as a source of food

strands of cytoplasm that extend through plant cells to connect to other cells

• circulation of cytoplasm caused by shortening and lengthening of "microfilaments" of actin
• motion of the chloroplasts (and other organelles) around the periphery of the cell

circular, cannot distinguish any structures

(a ton of tiny circles with cell walls-the dark outside)

red pigmentation, does not move out of cell with water

(looks like red bricks, the outline of each is cell wall, the nucleus is the dark circles, and the cytoplasm is the area inbetween)

be able to label the cell wall, cytoplasm, chloroplasts, and plasma membrane

• utilizing oxygen
• includes cellular respiration, krebs, and electron transport chain

• without oxygen
• include fermentation and glycolysis

cellular respiration is aerobic and gives greater yield of ATP, and fermentation is anaerobic

We predicted that beer yeast will ferment faster than wine yeast, and we experimented having 4 different tests tubes with different amouts of yeast and glucose solution. There was a control tube for each yeast, and the results supported the hypothesis

• absorption pattern for a particular pigment, showing the relative absorbance at different wavelengths of light
• can be determined with a spectrophotmeter or colorimeter

• a graph that illustrates the efficacy of different wavelengths of light in promoting photosynthesis
• the efficacy of various wavelengths of light is measured by the production of oxygen and the clustering of bacteria

blue because black absorbs all wavelengths even white

• Because it stains starch purple-black
• a change fromthe yellow-amber color of the iodine solution to a purple-black solution is a positive test for starch production which determines photosynthesis

The most polar will travel the slowest up the chromatography paper compared to the least polar will travel the highest on the chromatography paper over the same amounts of time

• Use a spectrophotometer or colorimeter
• List the pigments extracted and the optimum wavelengths of light for each
• Decide which pigment is most important in photosynthesis (the one that has a higher abosorbion at more wavelengths)