Life Science Lab Review

Test: Wednesday march 28 2012Life Science Lab Review

Microscopes allow the user to visualize objects or structures too small to be seen by the naked eye. The word microscopic means invisible to the eye unless viewed by a microscope. What does a microscope do?#1SHOWNEXTMARK FOR REVIEWReview

Eyepiece tubeStageCondenser-B and Button-aDiaphragm leaver, leaver-A which reg. diaphragm-b

Label all the numbers

5. Eyepieces

6.Nose piece

7.Objectives

8.lamp-light source

Label all the numbers

9. Arm

10. Coarse adjustment knob

11. Fine adjustment knob

12. Light adjustment button

13. Specimen holder

14. Y axis and x axis knob

15. Power cord

Label all the numbers

4

4x objective lens (used for scanning the slide at low magnification and used dry)

2. 10x objective lens (weak magnification, dry)

3. 40x (high magnification, dry)

4. 100x (very high magnification, oil immersion lens)

What are the most common objective lenses? And what are they used for?#5SHOWNEXTMARK FOR REVIEWReview

The total magnification of the image you are viewing under the microscope can be calculated in the following way:

eyepiece magnification X objective magnification

Example: The eyepiece lens has a magnification 10x and if you are using a 40x objective lens then the total magnification = 10 X 40= 400X.

What is TOTAL MAGNIFICATION? And what's the equation ?#6SHOWNEXTMARK FOR REVIEWReview

Know the following!

the buccal mucosa (mouth) of the newborn can be swabbed to collect epithelial cheek cells. The cells will then be used to looked for BARR bodies in the nucleus. These BARR bodies represent an X chromosome that has been inactivated (referred to as X inactivation or lyonization). To ensure that the results are real, a total of about 100 nuclei are counted (around 50 nuclei per slide) for the BARR bodies test. Any broken, folded or excessively granulated nuclei are ignored. Also, areas of the slide which may be heavily contaminated by debris (for example folded cells, multiple cells on top of each other or even bacteria) are also avoided. A nucleus is positive if it contains a BARR body that is clearly defined, darkly stained and touching the nuclear membrane as seen here (arrows point to BARR bodies).

What is the BARR test?#8SHOWNEXTMARK FOR REVIEWReview

The barr test is a test used to determine the chromosomal sex of an individual. What is the BARR test used for?#9SHOWNEXTMARK FOR REVIEWReview

BARR bodies- inactivated X chromosomes, what is it stained with?

Cresyl violet stained

The following formula is used to determine the % of cells that are positive for BARR bodies:

If there are 0-2% positive cells after counting at least 100 nuclei, the result is considered negative meaning the infant has XY chromosomes and is genetically (ie chromosomally) male.

What is the formula for the BARR test?#11SHOWNEXTMARK FOR REVIEWReview

consider the following results after viewing epithelial cells swabbed from the cheek of an infant with ambiguous genitalia:

The total number of cells counted is 102 and the total number of cells (or nuclei) containing BARR bodies is 1. Using the formula above, the % of positive cells is 0.98% meaning the test result is negative.

Example

11-19%If the child is genetically female,what % of cells would contain BARR bodies?#13SHOWNEXTMARK FOR REVIEWReview

Osmosis is the movement of water across a semi-permeable membrane moving from a HIGH concentration to a LOW concentration of solutes.

What is osmosis?#14SHOWNEXTMARK FOR REVIEWReview

1. remain normal (when it is placed in an isotonic solution)2. undergo crenation (when placed in a hypertonic solution)3. undergo hemolysis (when placed in a hypotonic solution)Cell membrane permeability allows a cell to adjust to its environment through osmosis. Depending on the environment, the cell can adopt three core states:#15SHOWNEXTMARK FOR REVIEWReview

Isotonic Normal is to #16SHOWNEXTMARK FOR REVIEWReview

Hypertonic As crenation is to #17SHOWNEXTMARK FOR REVIEWReview

hypotonicAs hemolysis is to #18SHOWNEXTMARK FOR REVIEWReview

LAB 2- HEMATOLOGY

Blood cells+cell fragments suspended in plasma (rbc, wbc, platelets)What are formed elements?#20SHOWNEXTMARK FOR REVIEWReview

Whats this? FORMED ELEMENTS!!!Describe why!

RBCPlatelets Neutrophils

And this?Eosinophilbasophil lymphocyte

And lastly this?Monocyte

NeutrophilsEosinophilsBasophils Which of the above were granulocytes?#24SHOWNEXTMARK FOR REVIEWReview

MonocyteslymphocytesWhich of the above were agranulocytes?#25SHOWNEXTMARK FOR REVIEWReview

The hematocrit is the percentage of formed elements in blood Know how to read hematocrit levels and what it means! is determined by centrifuging a blood sample so that all the formed elements are packed down. Because RBCs form 99.9% of the formed elements, the hematocrit is commonly reported as the percentage of RBCs in the blood. Define HEMATOCRITE!#26SHOWNEXTMARK FOR REVIEWReview

Hemoglobin is a protein found in the RBC and is responsible for the cell's ability to transport oxygen and carbon dioxide. The hemoglobin molecule consists of heme and globin. The globular protein is called globin and is composed of 2 alpha and 2 beta chains of polypeptides. Each chain contains a single molecule of heme (pigment complex) and each heme holds an iron ion that can interact with oxygen. In other words, each hemoglobin molecule contains 4 subunits of heme and 4 chains of globin protein.

Define HEMOGLOBIN!!#27SHOWNEXTMARK FOR REVIEWReview

Identifying blood types! #28SHOWNEXTMARK FOR REVIEWReview

It is like an id tag for the type of rbcs you have.

Your own immune system ignores the surface antigens (or agglutinogens) on your own RBCsWhat is an antigen?#29SHOWNEXTMARK FOR REVIEWReview

your plasma contains antibodies (or agglutinins) that will bind to and destroy foreign RBCs Example- type a containts type b antibodies, and these antibodies will bind to the b rbcs causing them to clump together (agglutinate) and hemolysis [rupture]What is an antibodie?#30SHOWNEXTMARK FOR REVIEWReview

In an incompatible transfusion, agglutination of blood cells occurs due to an antigen-antibody interaction. This results in the destruction of cells via hemolysis. This occurs because the antibodies present in the recipient's plasma will attach to the surface antigens of the donor RBCs that have been transfused to her. How does an incompatible blood transfusion work?#31SHOWNEXTMARK FOR REVIEWReview

EXAMPLE For example, Angela has type A blood and therefore has anti-b antibodies in her plasma. She accidentally receives type B blood (remember that when you received a blood transfusion, you are only receiving RBCs, not the donor's plasma). The antibodies in Angela's plasma recognize the surface antigen B on the type B donor blood as foreign and as a result, Angela's antibodies attack the type B RBCs causing them to clump or even break up. Clumps and fragments of these RBCs can plug small blood vessels found in kidneys, lungs, heart or brain, thus damaging or destroying important life sustaining tissues. Such cross-reactions can be prevented by transfusing compatible blood.

Presence = Rh positive Absence(on surface of rbcs= rh negative

Rh system (Rh factor) #33SHOWNEXTMARK FOR REVIEWReview

readddUnlike the ABO system, if an Rh- individual receives Rh+ blood, the Rh negative individual will first produce antibodies to the Rh surface antigen but hemolysis does not occur immediately following the first transfusion. However ,during a second transfusion of Rh+ blood, the Rh antibodies produced during the first transfusion will now react with the Rh surface antigen present on the Rh positive RBCs and cause hemolysis.

Erythroblastosis fetalis-can occur when an Rh- mother carries an Rh+ foetus. When this woman delivers her first Rh+ baby, fetal and maternal blood mix when the placenta breaks down. The presence of the babies Rh+ blood stimulates the mother's immune system to produce anti-Rh antibodies. If another pregnancy now involves a Rh+ baby, the mom's anti-Rh antibodies can cross the placenta and enter the foetal bloodstream. These antibodies will destroy the fetal RBCs and produce a dangerous anemia (hemolytic disease of the newborn) that can result in brain damage and death. Describe hemolytic disease of the newborn (HDN) what is it also called???#35SHOWNEXTMARK FOR REVIEWReview

To avoid this what would you give? The maternal production of anti-Rh antibodies can be prevented by administering such antibodies (known as RhoGam) to the mother near the end of pregnancy and during and after delivery. These antibodies will bind to and can destroy any fetal RBCs that cross the placenta before these RBCs have a chance to stimulate the mom's immune system to produce her own antibodies to the Rh factor. This relatively simple procedure has almost completely prevented HDN mortality caused by Rh incompatibilities.

Lab 3, urinalysis

Quantity Colour Odour Tubidity (transparency)Specific gravity (density)

The quantity of your urine is quite poor as the colour is quite dark and the Tubidity is also non exzistant And the specific gravity is quite high What are the 5 physicle properties of urine ?! (5 senses :P ) no taste 2 sights #38SHOWNEXTMARK FOR REVIEWReview

Quantity aka rate of production! Taken over a period of time to develop a rateNorm - 600 to 2000 ml per day (or 1.1 ml per minute)Equation: (know how to use)

In this equation Time A= time of urine sample collection, Time B= time of last urination before sample collectionIncreased urine = diabetes, chronic infections, excessive fluid intake and diureticsDecreased urine= acute infections, dehydration and shock

39

reddish, pinkish or brownishred or pink =blood (hematuria) brownish urine =hemoglobin (hemoglobinuria)

If you have ever eaten large enough amounts of highly pigmented food like beets and rhubarb, or taken certain medications or vitamins that contain pigments, you may also notice a change in the colour of urine that is not due to pathological abnormalities but simply to the presence of these pigments in your urine.

Whats the colour of abnormal urine?#40SHOWNEXTMARK FOR REVIEWReview

Transparency!Urine should be clear and not cloudy as this can indicate the presence of suspended material such as mucus, bacteria, yeast or various types of cellsTurbid urine is therefore indicative of microbial infections or abnormal glomerular filtration at the level of the nephronTurbidity aka?#41SHOWNEXTMARK FOR REVIEWReview

Abnormal urine can emit a fishy or very strong ammonia odour that is a result of the transformation of nitrogenous substances by bacteria. In other words, the strong smell can indicate a bacterial infection: bacteria degrade the substances that you eat and in turn cause your urine to smell fishy or strong. Abnormal Odor? #42SHOWNEXTMARK FOR REVIEWReview

Specific gravity is the weight of the urine compared to an equal amount of water. It is a reflection of the amount of solutes present in the urine. The density of water is 1 while the normal range of specific gravity for urine is 1.001-1.035. Because the specific gravity is higher than 1, this indicates that urine is normally denser than water because the solutes in the urine, like ions, metabolites and nitrogenous wastes, increase its density. Extreme levels of solutes in urine can cause the solutes to precipitate (fall out of solution).

What is specific gravity?#43SHOWNEXTMARK FOR REVIEWReview

NitritesProteinsGlucose pH ketones urobilinogen bilirubin blood white blood cellsName 9 chemical properties of urine! #44SHOWNEXTMARK FOR REVIEWReviewNice pregnant girls possess kinda unreliable big boys, wow.

the conversion of nitrates (commonly found in urine) to nitrites is carried out by gram (-) bacteria like E. coli. This bacteria is commonly the causative agent of urinary tract infections

if the urine does not stay in the bladder long enough to produce nitrites, the test will always be negative (even in the presence of a bacterial infection)

to increase the reliability of this test, it should be carried out with the first morning urineNitrates (briefly describe)#45SHOWNEXTMARK FOR REVIEWReview

the concentration of proteins found in the urine is usually not detected by this band on the urinalysis reagent strip

the presence of proteins in the urine is called proteinuria and is caused by certain renal pathologies such as urinary tract infectionsProteins (briefly describe)#46SHOWNEXTMARK FOR REVIEWReview

normally glucose cannot be detected in urine. However, when the glucose reabsorption capacity is exceeded, glucose stays in the renal tubules and can be then found in urine specimens. This is caled glycosurea and is associated with insulin dependent diabetes, hepatic disease and often occurs in pregnancy.Glucose (breifly describe)#47SHOWNEXTMARK FOR REVIEWReview

the pH range of urine is between 5 and 9

urine is normally at a pH of 6 (slightly acidic)

a low pH normally indicates renal compensation for a high blood H+ concentrationpH (briefly describe)#48SHOWNEXTMARK FOR REVIEWReview

the band on the strip that indicates ketones in the urine is actually reacting to diacetic acids and acetone. These by-products of lipid metabolism are always present in small concentrations in blood but not in urine.

diabetics and those suffering from abnormal carbohydrate metabolism will have ketone bodies in the urine

Ketone bodies- briefly describe#49SHOWNEXTMARK FOR REVIEWReview

by-product from hemoglobin degradation

Urobilinogen- describe#50SHOWNEXTMARK FOR REVIEWReview

the presence of bilirubin in the urine can indicate hepatic diseases such as hepatitis, cirrhosis and/or bile obstruction leading to high bilirubin concentrations

even very sensitive detection methods cannot normally detect the presence of bilirubin in the urineBilirubin- describe#51SHOWNEXTMARK FOR REVIEWReview

the reactive band on the strip indicates the presence of hemoglobin (hemoglobinuria) and the presence of RBCs (hematuria)

the presence of blood in urine is abnormal and can be due to hepatic disease , urinary tract pathologies or vascular damage in the urinary systemBlood-describe#52SHOWNEXTMARK FOR REVIEWReview

excess WBCs in the urine indicates renal infection, inflammation or UTIs.

the reagent strip remains negative in 80% of women with serious renal infections.WBCs - describe#53SHOWNEXTMARK FOR REVIEWReview

RBcs

Squamous epithelial cells

Transition cells, caudate

Transitional cells, spherical

Budding yeast Recognize the different elements found in a urinary pellet #54SHOWNEXTMARK FOR REVIEWReview

12345

Lab 4, Acid base balances

The pH scale has a range from 0 to 14. A pH of 7, which is in the middle of the scale, represents a neutral pH whereas all values lower than 7 (0.0-6.9) are acidic because of the high concentration of hydrogen ions [ H+]. pH values from 7.1 to 14.0 are considered basic due to the very small amounts of [ H+] present. The pH scale: range? Where is neutal? Acidic? Basic? And talk about [H+]#56SHOWNEXTMARK FOR REVIEWReview

Buffers are solutions containing a mixtures of chemical compounds that are used to maintain a certain pH in a solution. Buffers prevent major changes or deviations in pH when small amounts of acids or bases are added.

What is a buffer?#57SHOWNEXTMARK FOR REVIEWReview

A strong acid or base is one that completely dissociates (100%) in solution.

A weak acid or base is one which dissociates very little (incompletely) in solution.What is a strong acid/base? How about weak?#58SHOWNEXTMARK FOR REVIEWReview

Phosphate buffer system

Protein buffer system

Bicarbonate-carbonic acid buffer systemBody contains which 3 different buffer systems that work to maintain an optimum pH in your body?#59SHOWNEXTMARK FOR REVIEWReview

Strong acid+weak baseweak acid + salt

Strong base+weak acid weak base + water

Weak acid+weak baseweak acid+sodium ion+acetate ion

Prevents a large change by doing the aboveThe phosphate buffer system, understand how it works #60SHOWNEXTMARK FOR REVIEWReview

Proteins are amphoteric molecules meaning that they can behave both as acids or bases to maintain the pH in your body:

Carboxyl group of protein releases h+ when ph increases and acts as an acid Amine group of protein accepts h+ when ph decreases and acts as a base

The protein buffer system, understand it #61SHOWNEXTMARK FOR REVIEWReview

Carbon dioxide+water carbonic acid (weak acid)- hydrogen ion + bicarbonate (weak base)

This buffer system uses carbonic acid and bicarbonate to maintain an optimum pH in your body:

The bicarbonate-carbonic acid buffer system, understand #62SHOWNEXTMARK FOR REVIEWReview

Lab 5- microbiology

Spherical (coccus)Rod shaped (bacillus)Spiral (spirillum)

Name the 3 most common bacterial shapes ! #64SHOWNEXTMARK FOR REVIEWReview

Diplo (pairs)

Staphylo (grape-like clusters)

Strepto (chains)Name the following arrangements of bacteria #65SHOWNEXTMARK FOR REVIEWReview

The names of bacteria tell you about their shape and arrangement. For example, the Staphylococcus species are grape-like, spherical bacteria whereas the Streptobacillus species look like chains of rod shaped bacteria. How do you name bactera?#66SHOWNEXTMARK FOR REVIEWReview

Allows microorganisms to grow in a petri dishArtificial media does what?#67SHOWNEXTMARK FOR REVIEWReview

Gelationus, red seaweed extract made of agarose (polysaccharides) and agarpectin

Used to make liquid broth/solid media What is agar?#68SHOWNEXTMARK FOR REVIEWReview

nutrient agar (NAP)-used to grow almost all types of bacteria) and blood agar (BAP) (sheeps blood) that can be used to distinguish between various hemolytic bacteria.

What are 2 common agars used to grow bacteria in? what are they used for?#69SHOWNEXTMARK FOR REVIEWReview

1. Size : diameter in mm.2. Form : viewed from top of plate; several different types (see table 1 below)3. Elevation : what does the colony look like if viewed from the side of the plate (see table 1 below)4. Margin: edge of colony (see table1 below)5. Colour6. Density : whether it is opaque, transparent, translucent7. Surface : shiny or dull, smooth or rough8. Consistency: includes the followingButyrous- the consistency of soft butterSlimy- clings to loop when touched and forms strings when loop is withdrawnFriable- brittle; when touched with a loop it crumbles into several pieces; the whole colony may move a short distance before this happensMembranous- when touched with a loop, it sticks to the medium or the entire colony moves without crumbling into

Gross colony characteristics #70SHOWNEXTMARK FOR REVIEWReviewSee from effacement moms continuing dilation so constantly

Know chart

Answer/ Info to show up when Show Is pushedEnzymes produced by bacteria as a defense mechanism: we can test the enzymes to find out which type of bacteria species it is. #72SHOWNEXTMARK FOR REVIEWReview

Enzymes catalase breasks down potentially toxic hydrogen peroxide (h2o2) into harmless o2 and water (h20)catalase positive= small bubbles of o2 released Catalase negative= no response-all streprococci= catalase negative -all staphlococci= catalase positive

Enzymes produced by bacteria #73SHOWNEXTMARK FOR REVIEWReviewCatalase enzyme, Positive Negative

Defense mechanism

Bacteria partially lyse Rbc- greenish culture

Complete lyse- clear visible zone

No lysis- looks normal Hemolytic enzymes#74SHOWNEXTMARK FOR REVIEWReviewWhy do bacteria produce enzymes?Alpha hemolysisBeta hemolysis Gamma hemolysis

Thick pepidoglycan wall

Crystal violet stain/iodine fixative (becomes fixed to cell wall)

Purple

Because of crystal violet absorbed into cell wall and unaffeceted by alcohol GRAM +#75SHOWNEXTMARK FOR REVIEWReviewCell wallStain usedColour displayedWhy?

Thin pepticloglycan wall and external lipopolysaccharide layer

Pink

Crystal violet stain/iodine fixative

Washed away with alcohol because its unable to retain dye (thin cell wall) pink because of saffronin (counter stain)GRAM - #76SHOWNEXTMARK FOR REVIEWReviewCell wall Stain usedColour displayed Why?

Lab 6: GBS

Antigen:antibody reaction

Streptococci

GBS is long chains of cocci (spheres)Definitive ID of GBS: latex agglutination test or Coagulation test #78SHOWNEXTMARK FOR REVIEWReviewWhat is it based on?

2. Determines if bacteria is?

3. GBS is_________________?

Identifies bacteria of the Lancefield group b I. Arrow shaped hemolytic activity ii. No arrow= gbs

Gbs is camp+|

Definitive ID of GBS: CAMP test #79SHOWNEXTMARK FOR REVIEWReviewWhat does it identify ?

Response for i. + , ii.

GBS is _______________.

Catalase negative- no bubbles Preliminary ID of GBS: Catalase test #80SHOWNEXTMARK FOR REVIEWReviewWhat is the test result for identifying GBS?

Gram positivePreliminary ID of GBS: Gram staining#81SHOWNEXTMARK FOR REVIEWReviewGBS is?

i. neomycin, ii. Nalidixic acid (NNA)

Placed in a candle jar to decrease oxygen and increase CO2

Hemolytic activity, gbs is beta hemolytic Preliminary ID of GBS: BLOOD AGAR PLATES (BAP)#82SHOWNEXTMARK FOR REVIEWReviewSupplemented with i. ii.

Procedure?

Notes what activity?

Gbs produces red pigment (Grenadine)

Used to differentiate gbs from other pathogenic bacteria Gbs colonies are orange-red; other colonies remain white

Preliminary ID of GBS: Granada Agar#83SHOWNEXTMARK FOR REVIEWReviewWhat pigment?Use?GBS produces ______ colonies?

Blood agarMacconkey agarTrypticase soy agarSabourad agar Various growth media (name four and describe)#84SHOWNEXTMARK FOR REVIEWReviewenriched and differential necause it helps distinguish between hemolytic bacteria, appears red selective inhibits g+, favors g-, distinguishes lactose fermentors\non-ferm. Appears pink, appears pinkish favors production of pigment by bacteria complex, appears yellowish acidic, favors growth of fungi appears pale yellow

Purpose: to isolate pure single colonies in streak (5/e)- they can be re-streaked on another plate for further study Streak plate method #85SHOWNEXTMARK FOR REVIEWReview

The EndREVIEWEND