BIOL 103 Quiz II

Which color change represents a positive reaction for the presence of protein using the Biuret test?

Color change from blue to purple

A group of three nucleotides acts as a "code word" or template for making

one amino acid.

Enzymes are

proteins.

T/F The formation of an orange or purple color after the addition of iodine indicates that a sample contains lipids.

False--Iodine is not used to detect the presence of lipids.

Applications of transgenic organisms

Transgenic organisms are utilized for many applications. In agriculture, transgenic plants contain genes that make them frost, drought, pest, and disease resistant. In medicine, the human insulin gene is inserted into bacteria. These bacteria grow and divide rapidly, expressing large quantities of this protein. We then harvest this insulin product and use it for the treatment of diabetes.

Proteins are polymers composed of

amino acids.

The sequence of __________ in nucleic acids encodes a specific order of amino acids for making a protein.

nucleotides

During translation, adenine in mRNA pairs with ________________________ in tRNA, and guanine pairs with ________________________.

uracil; cytosine

Which of the following binds to the active site of an enzyme?

Substrate

Transcription

The process of copying the DNA so that the information can leave the nucleus

When viewing Elodea under a microscope, what is the most likely identity of green, round structures inside of the cell?

chloroplasts

The structure that easily distinguishes a plant cell from an animal cell is

chloroplasts.

Which reagent is used to detect the presence of starch?

iodine

DNA is used as a template for making

proteins and RNA.

Scientists often want to know if the transgenic organism can pass its new traits on to its offspring and future generations. Considering life history traits (i.e. birth rates, death rates, life span, etc.), which would be a better candidate to get this information: bacteria or fish? Why?

Bacteria can see to transformation, a natural process that can be utilized in the laboratory to insert medicinally utile genes into bacterial cells that then yield a particular protein, like insulin or human growth hormone. Correspondingly, transformation can be utilized in genetic engineering wherein plasmids, circular DNA inherently seen in some bacteria, can be engineered to carry genes via one organism into a bacterial cell. Addedly, bacteria reproduce asexually, by simple division, to reproduce copiously and in no time, allowing them to be more appropriate experimental testees for investigating whether the transgenic organism can pass its new traits on to its offspring and future generations. As bacteria exist as single-celled organisms, developing transgenic bacteria, as seen in this experiment, can be comparatively easy, but to create a transgenic animal, like fish, multi-celled organisms whose numerous cells the new gene would have to be inserted into, would, for sure, prove a challenge for scientists and experimenters. Bacteria reproduce and mature much more rapidly.

Which color change represents a positive reaction for the presence of starch using the iodine test?

Color change from amber to blue/black

A given enzyme works on

one type of substrate.

Match the inoculated agar plates with their growth after incubation. -pGLO on LB/amp +pGLO on LB/amp -pGLO on LB +pGLO on LB/amp/ara Green fluorescent bacterial colonies Very dense white bacterial colonies No growth White bacterial colonies

+pGLO on LB/amp/ara - Green fluorescent bacterial colonies -pGLO on LB - Very dense white bacterial colonies -pGLO on LB/amp - No growth +pGLO on LB/amp - White bacterial colonies

Liz is interested in the relative sugar concentration of her favorite sodas. She mixes a standard amount of each soda with a standard amount of Benedict's reagent, heats the samples in boiling water for five minutes, and observes the color reactions. Place the soda brands in order of increasing sugar concentration (lowest to highest). Brand D (Blue reaction color) Brand C (Green reaction color) Brand X (Red reaction color) Brand M (Yellow reaction color)

1 - Brand D (Blue reaction color) 2 - Brand C (Green reaction color) 4- Brand X (Red reaction color) 3 - Brand M (Yellow reaction color)

Each of the following steps are necessary in preparing and observing a wet mount. Place the steps in the correct order.

1) Obtain a clean slide and cover slip. 2) Using a transfer pipette, obtain a drop of specimen and place onto the center of the slide. 3) Carefully place the cover slip over the drop of specimen. 4) Observe preparation under the 10X objective lens. 5) Observe preparation under the 40X objective lens.

Indicate the correct order of steps as you bring an object into focus under high power.

1) Place slide on stage and secure with stage clips. 2) Turn on the light and center the specimen over the light source. 3) Focus specimen on scanning objective using coarse focus adjustment 4) Rotate to low power objective, then use fine focus to sharpen the image 5) Rotate high power lens into position. 6) Readjust fine focus under high power to produce the sharpest image.

Rank the following steps in the correct order that you would use to isolate DNA from strawberries. Wait for DNA precipitate to form Add ice cold ethanol to test tube Dissolve meat tenderizer and add it to test tube Transfer strawberry filtrate to test tube Spool DNA precipitate onto glass rod

1) Transfer strawberry filtrate to test tube. 2) Dissolve meat tenderizer and add it to test tube. 3) Add ice cold ethanol to test tube. 4) Wait for DNA precipitate to form. 5) Spool DNA precipitate onto glass rod.

There are four different types of macromolecules:

1. Carbohydrates (Sugars) 2. Lipids (Fats) 3. Proteins 4. Nucleic Acids

In the calculations above, what was the power of the eyepiece lens?

10x

Using the correct base pairing rules for DNA replication, what would be the complementary strand for the strand TACCGATGC?

ATGGCTACG

A valuable artifact has been stolen from the museum (Case: Museum Theft). The three suspects each claim they were never at the museum at all, but they have shaky alibis. Investigators found DNA evidence on the scene from a coffee cup (Sample 1) and discarded chewing gum (Sample 2).

After comparing the DNA fingerprints from the two samples to the three individuals, you conclude that Sample 1 matches Individual C and Sample 2 matches Individual C.

Thirty years ago, a murder took place in a parking lot (Case: Parking Lot Murder). There were two suspects in the case: Alex and Bob. Based on eyewitness testimony and fingerprint analysis on the weapon, Alex was convicted and sent to prison for murder. Now, however, his lawyers have petitioned the state to revisit the case using modern DNA fingerprinting techniques. There is DNA from a blood sample and a hair sample found at the scene (Evidence 1 and 2), and you have DNA samples from Alex (Suspect A), Bob (Suspect B), and the victim. After analyzing these samples, what can you conclude?

Alex is exonerated; the evidence samples both match Bob's DNA.

Predict the lipid content of the following food items by ranking them in order from least to most lipid content. Explain your ranking by indicating the potential results from the lipid test performed here. Donut, piece of white bread, saltine cracker, bagel.

All the food items contain at least some fat; however, saltine crackers, white bread, and bagels have a comparatively low lipid/fat content donuts. White bread seemingly has the least fat, followed by the saltine cracker, and then the bagel. On the other end, donuts--doused in shortening--can be seen as a highly fatty food. Appropriately, a lipid test on a white bread piece, a saltine cracker, and a bagel would presumably yield only a faint stain on the paper--faintest on the bread, a little less faint on the saltine cracker as compared to the bread, and a bit more visible on the dense bagel---while a lipid test on the fatty donut would yield a greasy stain.

Negative Control

Any procedure that is known to NOT produce the desired result. A negative test result means what you are looking for is NOT present.

Positive Control

Any procedure that is known to produce the desired result. A positive test result means what you are looking for is present.

Name and describe 2 applications for DNA fingerprinting. In other words how is DNA fingerprinting useful in everyday life?

DNA fingerprinting can see to use in various circumstances, such as forensics and crime scene investigation, paternity testing, ancestry testing, genetic research, and pinpointing species sameness to aid in taxonomical organization. DNA epitomizes as an instrumental investigative tool for the reason that, other than identical twins, no two persons have the same DNA. So, DNA collected at a crime scene can be linked to a perpetrator or used to prove a suspected person as innocent. Similarly, as genetic material inherited via mother and father, DNA can see to use for paternity testing. A DNA paternity test looks to DNA taken via hair, blood, saliva, cheek swab, etc. to discern whether a man remains a child's biological father. DNA fingerprinting can be used to identify a criminal of a violent act, to determine paternity and ancestry, to identify remains, identify skins, tusks, furs and other animal parts taken by poachers.

Your grandparents don't understand DNA fingerprinting at all. They call it that "new fancy science technology mumbo jumbo." Explain what DNA fingerprinting does, how it works and how you can tell who committed a crime.

DNA fingerprinting externalizes as an investigative approach utilized to determine a connection between DNA/genetic sample and a suspected person in a crime investigation. A DNA sample derived via a crime scene sees to comparison with a suspected person's DNA sample. Should the two DNA swatches match, then we can reason that the sample stemmed via the suspect. Contrarily, should the two DNA swatches mismatch, then that means that the sample has not stemmed via the suspect and involves someone else. Thus, DNA fingerprinting can be used to determine who committed a crime. DNA fingerprinting breaks DNA collected from items at a crime scene and breaks up the DNA into pieces of different sizes. The DNA is charged and it is loaded onto a gel electrophoresis which applies an electrical current to more the negatively charged DNA down the gel. The DNA pieces move based on size with small fragments of DNA moving quickly and showing up at the bottom of the gel and large pieces moving slowly and staying near the top of the gel. Samples from the evidence are compared to samples from the suspects and patterns are noted between the bands on the gel.

For DNA fingerprinting, what does each band on the gel represent?

DNA fragment

If we extracted DNA from a strawberry as described and repeated the same procedure on a steak, would the DNA look different? Why or why not? What about the DNA makes the strawberry and steak (i.e. cow muscle) different?

DNA is universal. Thus if we repeated this procedure on any living organism, the extracted DNA would look exactly the same. The different genetic code that distinguishes organisms, tissues, cells, etc. is the order of nitrogen bases.

In sequential order, what are the three basic steps of PCR?

Denature DNA, Primers, Extend DNA

A negative control is a sample that you know will give you a negative result. You are testing for the presence of proteins, simple sugars, starch, and lipids in various foods. What would be the best negative control for this experiment?

Distilled water, because it does not contain any of the molecules you are testing for.

Nucleotide triphosphates (dNTPs) are added to the growing DNA strand during the _______________ phase.

Extension/elongation

T/F Enzymes are consumed in chemical reactions and must therefore be replenished.

False--Enzymes are defined as catalysts, which means that the enzyme not only increases reaction rates but also are not used up or changed during the process and can be used multiple times.

A small amount of lipase, called gastric lipase, is made by cells in your stomach. The average temperature of the stomach is 37oC(98.6oF). This enzyme specifically digests butterfat in your food. Lipase is an enzyme that breaks down dietary fats into smaller molecules called fatty acids and glycerol. This enzyme was extracted by Jane and added to butter (a fatty food), then left on ice for thirty minutes. The reaction did not occur. What property of enzymes explains why the reaction did not occur? Also was this a catabolic or anabolic reaction? Explain.

Gastric lipase operates/reacts in temperatures at or near 37 degrees Celsius--the average temperature seen in the stomach where the enzyme originates--and potentially reacts even faster at higher temperatures up to a certain point. So, exposing the enzyme to lower, colder temperatures via leaving butter-added enzyme on ice for thirty minutes will not yield a reaction. As lipase breaks down dietary fat into smaller molecules called fatty acids and glycerol, this reaction can be seen as a catabolic reaction. (Catabolism breaks down complex molecules into simpler ones). The reaction did not occur because enzymes are sensitive to environmental conditions. In this case, the temperature was too cold. This enzyme needs a temperature around that of human body temperature to function optimally. This is a catabolic reaction because better fat is broken down into fatty acids and glycerol.

After focusing on an object with the low power objective lens, you are trying to bring it into focus under the 40x objective lens, but the field of view is very dark. Which of the following may remedy this problem?

Increase the light intensity.

What does the acronym PCR stand for?

Polymerase Chain Reaction

A change in what component of microscopy influences the apparent size of the objects being viewed?

Magnification

Transgenic Organisms

Organisms that contain DNA from 2 or more sources

How does the DNA rate of travel differ for small DNA fragments and large DNA fragments?

Small fragments travel farther than large fragments.

When testing the temperature of catalase in the enzyme lab, why did the higher temperature affect the catalase activity?

Some of the catalase enzymes were denatured.

Match the names of the microscope parts in column A with the descriptions in column B. Place the letter of your choice in the space provided. 1 Nosepiece 2 Arm 3 Stage (slide) clip 4 Eyepiece (ocular) 5 Field of view Holds a microscope slide in position Contains a lens at the top of the body tube Serves as a handle for carrying the microscope Part to which the objective lenses are attached Circular area seen through the eyepiece

Stage clip--Holds a microscope slide in position Eyepiece--Contains a lens at the top of the body tube Arm--Serves as a handle for carrying the microscope Nosepiece--Part to which the objective lenses are attached Field of view--Circular area seen through the eyepiece

Looking at your data collected from the gel electrophoresis, which patient do you think has the best ability to resist illness? Explain.

TNF alpha exists as an important protein that helps the body resist disease. TNF 1 represents the normal gene whilst TNF 2 comes as a gene involved in lowered capacity to resist illness. Sample 1 contained TNF 2, sample 2 contained TNF 1, and sample 3 contained TNF1 and TNF 2. Correspondingly, a patient with the DNA seen in sample 2 should have the optimum capacity to resist illness due to the normal TNF gene existent in his/her DNA. TNF 2 is a gene associated with a reduced ability to resist illness. Patient 1 had two copies of TNF 2 and no copies of the functional TNF 1. While patient 3 also had a copy of TNF 2, they also have a copy of the "healthy" gene TNF 1.

Kathy wants to cut sugar out of her diet. She realizes that she consumes more simple sugars in her beverages than she realized. Predict the amount of simple sugar in each of these beverages by indicating the color change you would expect to occur with the Benedict's solution. Explain your observations. Diet iced tea, Milk, Orange juice, Coffee with one sugar.

The Benedict test detects simple sugars or monosaccharides via changes in color to the solution. Blue represents no simple sugars. The color then progresses through green/yellow, orange, and red as simple sugar content increases. Diet iced tea contains 0g sugar, so the Benedict solution's color should stay blue. Milk has approximately 12g sugar; orange juice, particularly Tropicana orange juice, has about 22g sugar; and coffee, supposing black coffee with one tsp sugar, has an anticipated 4g sugar. Accordingly, the coffee should yield a green/yellow color; the milk should turn the Benedict's solution orange; and the Tropicana orange juice should change the solution to red. Diet iced tea - blue. There is no sugar added, only artificial sweaters which are not sugars. Milk - orange. Milk sugar is lactose. Orange juice - red. Fruits have a lot of natural sugars which accounts for their sweet flavors. Coffee with one sugar - green/yellow. Coffee alone doesn't have sugar but you are adding sugar.

While looking at the gel casting tray on the UV table, the TNF2 DNA fragment moved further than the TNF1 DNA fragment. Which of the following can you conclude to be true?

The TNF2 DNA fragment was smaller than the TNF1 DNA fragment.

When biuret reagent is added to a solution containing protein, the solution turns pink or purple. In the absence of protein, the solution is blue. Biuret reagent was added to solutions that may or may not contain protein. What is the dependent variable in this experiment?

The color change from blue to purple

Translation

The copy of the gene made via transcription can direct the formation of a sequence of amino acids which creates the protein. This process occurs in the ribosome.

What is DNA isolation?

The extraction of DNA from viruses or cells

Anticodon

The part of a tRNA that matches a codon

How does the concentration of the substrate in an enzyme-controlled chemical reaction change over time?

The substrate concentration will decrease.

Despite round-the-clock security, in one month three rhinoceros were slaughtered by poachers in several wildlife parks in Africa (Case: Rhino). Their horns were cut off and the animals died. The next month, customs agents in Asia discovered someone trafficking in vials of so-called "medicine" derived from rhinoceros horn. The trafficker claimed that the rhinoceros horn was an antique family heirloom. Compare the DNA from the seized vials (Horn Samples 1 and 2) and the three rhinoceros killed recently (Rhinos A, B, and C). What can you conclude?

The vials were both from Rhino A.

Codons

Three nucleotides that each stand for one specific amino acid

T/F A DNA fragment with 100 base pairs is smaller than a DNA fragment with 150 base pairs.

True

The police are investigating a murder that took place in a library (Case: Library Murder). They have DNA samples from two blood stains at the scene, as well as samples from two suspects and the victim.

Using the two primer sets for chromosome 5, and comparing the patterns on the gel, you can conclude that Evidence 1 matches Suspect 2 and Evidence 2 matches None of the above. When you choose a different set of autosomal primers to compare, the result is The same.

In DNA replication, _______________________ pairs with thymine, and cytosine pairs with _______________________.

adenine; guanine

Enzyme function is optimum

at specific pH and temperature ranges.

When Benedict reagent is added to a solution containing simple sugars, the solution turns green, orange, or red. In the absence of simple sugars, the solution is blue. Benedict reagent was added to solutions that may or may not contain simple sugars. The color change that occurs is considered the ______________________________________.

dependent variable

The Biuret Test

detects the presence and concentration of protein; the Biuret solution starts blue without protein and turns purple when protein is present

The Benedict Test

detects the presences of simple sugars or monosaccharides; the Benedict solution turns from blue to red in the presence of increasing amounts of sugar

The control used in the test for fats experiment was

distilled water.

A student is designing an experiment about cell size in organisms of different sizes. Her hypothesis is that larger organisms will have larger cells. She collects cheek cells from five different students in her class and estimates their size under the microscope.

height of human students

The Benedict's test indicates a positive result when the solution turns...

red, green, orange, yellow

In the DNA isolation process, the filtrate and reagents are kept in an ice bath because cold temperatures are required to

stabilize the DNA.

Polysaccharides are polymers composed of

sugars.

The DNA or RNA used in a PCR reaction is called the

template.

As the amount of substrate is increased in an enzyme-substrate reaction,

the amount of product increases.

Which of the following are functions of proteins?

- Catalytic (enzymatic) activity - Structural support - Transport of molecules/ions through blood and across plasma membranes

Which of the following are functions of lipids?

- Storage of energy - Membrane structure - Signaling molecules (such as hormones or neurotransmitters)

Which of the following are functions of carbohydrates?

- Storage of energy - Structural support

Which of the following samples could be utilized in DNA fingerprinting?

- Teeth - Hair - Tusks - Blood

What is the advantage of using a wet mount?

- The motility of a specimen can be viewed under a microscope. - The specimen can be viewed as living cells.

Complete the calculations for total magnification produced by various combinations of the eyepiece and objective lenses. Remember, to calculate the total magnification achieved when using a particular objective, multiply the power of the eyepiece by the power of the objective used.

- When the scanning (4x) objective is used the total magnification will be 40x. - When the low power (10x) objective is used the total magnification will be 100x. - When the high power (40x) objective is used the total magnification will be 400x. - When the oil immersion (100x) objective is used the total magnification will be 1000x.

Enzymes

- are specific for their substrates. - act as catalysts. - have a special shape that controls their function. - control the speed of reactions.

What may affect the rate of an enzyme-driven reaction?

- pH - Temperature - Concentration of enzyme - Concentration of substrate

The primer set labeled "X,Y" is for the gene AMEL, which is present on both the X and Y chromosomes. However, the copy of the gene found on X chromosomes has a 6 base pair deletion compared to the copy found on Y chromosomes. Based on this information, label the sex of each DNA sample from the Library Murder Case.

Evidence 1 Male Evidence 2 Female Suspect 1 Male Suspect 2 Male Victim Female A female sample will have only one band, since the allele on each of the X chromosomes will be the same size. A male sample will have two bands, since the allele on X and Y chromosomes are different sizes with the gene on the X chromosome being smaller.

Match the names of the microscope parts in column A with the descriptions in column B. Place the letter of your choice in the space provided. 1 Stage 2 Iris diaphragm 3 Objective lens system 4 Condenser 5 Adjustment knob Increases or decreases the light intensity Platform that supports a microscope slide Concentrates light onto the specimen Causes stage (or objective lens) to move upward or downward After light passes through the specimen, it next enters this lens system

Iris diaphragm--Increases or decreases the light intensity Stage--Platform that supports a microscope slide Condenser--Concentrates light onto the specimen Adjustment knob--Causes stage (or objective lens) to move upward or downward Objective lens system--After light passes through the specimen, it next enters this lens system

During the paper test, solution 2 left a faint stain behind and was determined to be milk while solution 4 left a very definite and greasy stain behind and was determined to be oil. What can be concluded about the lipid content of milk?

It contains a lower concentration of lipids than oil.

Where would the DNA be located within a eukaryotic cell?

Nucleus

What type of organism is Elodea?

Plant

T/F A drop of liquid that does not evaporate from brown paper after a 20-minute period at room temperature contains lipids.

True

T/F Gel electrophoresis is an important tool used in biotechnology for forensics and paternity test.

True

Archaeologists working on the Island of Ambrosia made a discovery of ancient human remains (Case: Lost Prince). Local islanders believe that these represent the Lost Prince of Ambrosia. Thanks to local funerary customs and the islands' unique climate, you have been able to extract DNA from the mystery remains as well as the remains from the former King and Queen, parents of the lost prince. There is also DNA available from unrelated Islanders (male and female). After analyzing these samples, what do you conclude?

The human remains are the Lost Prince, son of the King and Queen.

If you were to shine the UV light on the pGLO/bla DNA solution, you would not see any color. The DNA solution itself is clear. Describe why the plates glow while the DNA itself if colorless. Use the terms transcription and translation in your answer.

The plates glow whilst the DNA remains colorless for the reason that pGLO plasmid DNA, on its own, will not illuminate in reaction to ultraviolet light exposure. Rather, a protein, the green fluorescent protein gene, that the new DNA creates within the cells via transcription (RNA polymerase catalyzes mRNA synthesis using the gene's DNA) and translation (within ribosomes, a codon--a trinucleotide mRNA sequence that corresponds to a particular amino acid--will be matched with a tRNA anticodon to synthesize the protein) seems to yield luminescent/light-emitting properties in the bacterial colonies. This fluorescence epitomizes as a gene, and proteins express genes. The DNA must be transcribed and translated into a protein. It is the protein and not the DNA that glows.

When testing for starch within the potato and onion, the test tube containing potato turned purple while the test tube containing onion turned orange. What can you conclude about the amount of starch in these two vegetables?

The potato contained a higher concentration of starch than the onion.

To create a transgenic organism, you must insert the new gene into every cell in the organism. It was fairly easy to produce transgenic bacteria in this experiment but it would be difficult to produce a transgenic animal like GloFish® that are common at pet stores. (a) Why would this process be more difficult for fish? That is, how do bacteria and fish differ? (2 pt) (b) Considering your answer in part (a) above, when in an animal's life cycle (from conception to adulthood) would be the best time to genetically modify it? Explain. (2 pts)

To yield a transgenic organism, the new gene has to be inserted into each and every cell in the organism. Correspondingly, bacteria exist as unicellular organisms, so genetically-engineering a bacterium into a transgenic organism will involve implanting the new gene into a mere one cell whereas, for multicellular organisms such as a fish, the new gene will have to be inserted into all its numerous cells. Genetic engineering the multi-celled animal can best be achieved within the zygote life stage. As a zygote, the animal would be a single-celled organism. (a) Fish are multicellular and bacteria are single-celled. (b) It would be easiest to manipulate multicellular organisms at conception when they are a single-fertilized egg or a few-celled blastula/embryo.

In translation, what would be the correct tRNA anticodon for the codon ACC?

UGG

You are a crime scene investigator. You follow a suspect to a sandwich shop where he has lunch with two acquaintances. The group tosses most of their trash but leaves a few used napkins on the table. After they leave, you run to collect the napkins before they are thrown away in order to isolate DNA. Your suspect ordered a sandwich and chips, the unidentified woman ordered a salad with no dressing, and the unidentified man ordered a sandwich and an apple. Could you identify the suspect's trash by just examining the napkins? Explain.

Unlike his/her two acquaintances, the suspect ordered some chips. Chips contain fats or lipids, particularly oil. So, an oily spot should appear on the suspect's paper napkin, as a lipid (chips) that has been in contact with paper will result in an evenly distributed oily stain materializing on the paper after 15 minutes. The potato chips would leave grease stains on the napkins from the oil used to fry them.