PLTW - Principles of Biomedical Science Review

Flashcards for PLTW Principles of Biomedical Science End of Course Assessment Review

Name 5 pieces of evidence that might be obtained at a crime scene.

Hair, fingerprints, blood spatter pattern, saliva, digital evidence, DNA

What does a medical examiner look for when performing an autopsy?

Evidence of how a person died – manner, cause, and mechanism of death; toxicology, evidence of disease, evidence of injury, etc.

What is the difference between manner of death and cause of death?

Manner of death is the overarching reason (natural vs. unnatural). Cause of death is the specific reason (stroke, gunshot wound, etc.)

What is the mechanism of death?

The specific way the body died (exsanguination, asphyxiation, no blood flow to the brain, etc.)

If a body is found at 8 A.M. with a rectal temperature of 95.2 F, what is the approximate time of death?

Around 6 A.M. (Calculation: 98.4 – 95.2 / 1.5 = 2.13 hours since death)

Name the parts of a nucleotide.

Phosphate group, nitrogenous base, and a deoxyribose sugar (for DNA)

What charge does a phosphate group have?

Negative charge

Name all four bases of DNA and which bases are structurally similar to one another.

Adenine and Guanine are purines (double ring). Cytosine and Thymine are pyrimidines (single ring).

What are the base pairs of DNA?

A – T, G – C (Chargaff’s rule)

Which base is NOT present in RNA?

Thymine, replaced with Uracil

What are purines?

Adenine and Guanine (double ring structure)

What are pyrimidines?

Cytosine and Thymine (single ring structure)

What do restriction enzymes do?

They cut or digest a strand of DNA in particular places as they read the DNA strand.

What is an example of a restriction enzyme sequence?

HaeIII looks for the “GGCC” pattern and cuts between GG and CC

What is the purpose of gel electrophoresis?

It separates DNA molecules so they can be stained and visually seen to analyze the DNA.

What does gel electrophoresis help to do?

Match a person to an unknown sample, or view alleles in a genotype.

Which way does DNA run on the gel?

From negative end to positive end.

Why does DNA run a certain way on a gel?

Attracted to the positive side due to the slightly negative charge from the phosphate group.

How does DNA differ from person to person?

The sequence of base pairs is different for everyone.

Write the strand of DNA that would bind with this strand: GAATACGAT

CTTATGCTA

What is an independent variable?

The variable that is manipulated.

What is a dependent variable?

The variable that is measured.

What is a control group?

The group that does not receive the treatment.

What does RFLP stand for?

Restriction Fragment Length Polymorphism

How is RFLP used in DNA analysis?

Differences in the lengths of the DNA fragments are run through gel electrophoresis to identify suspects or alleles.

How are RFLPs created?

By digesting the DNA with restriction enzymes.

What can restriction enzymes determine when someone has a mutation for a genetic disease?

The cut there would show 2 fragments vs. the one long RFLP when run on a gel.

What is the genotype for Lane 3 in the FH electrophoresis results (Patient is heterozygous for FH)

Ff

What is the genotype for Lane 4 in the FH electrophoresis results (Patient has FH)

ff

What is the genotype for Lane 5 in the FH electrophoresis results (Patient is homozygous dominant)

FF

What is the genotype for Lane 6 in the FH electrophoresis results (Patient has FH)

ff

What is the genotype for Lane 7 in the FH electrophoresis results (Patient is homozygous dominant)

FF

What is the genotype for Lane 8 in the FH electrophoresis results (Patient is heterozygous for FH)

Ff

What does PCR stand for?

Polymerase Chain Reaction

What is the purpose of PCR?

To produce millions of copies of a specific DNA sequence from an originally small amount of DNA.

What is the difference between presumptive and confirmatory tests?

Presumptive suggests something is probably blood. Confirmatory tests confirm that it is blood specifically.

Name three types of presumptive tests.

Leukocrystal violet (LCV), Luminol, and Kastle Meyer

Name and describe the role of platelets.

Thrombocytes; tiny fragments of a cell that assist in blood clotting.

Name and describe the role of red blood cells.

Erythrocytes; transports nutrients/oxygen and remove wastes from the body

Name and describe the role of white blood cells.

Leukocytes; active in an immune response, part of the body’s immune system.

Name and describe the role of plasma.

Pale yellowish liquid portion of the blood that contains all the other components. Provides for sugars, lipids, amino acids, hormones, etc to travel.

Name and describe the role of hemoglobin.

A protein in red blood cells that allows oxygen to bind for transport.

Name and describe the role of hematocrit.

The proportion of red blood cells in the blood to total blood volume.

What blood type is the universal donor?

O negative

Why are people with Type AB considered the “universal recipient?”

They do not have any antibodies to A or B blood present therefore nothing would attack any of the other blood types.

You complete blood type testing and there is no agglutination with either anti-A or anti-B antibodies. What type of blood is present?

This would be type O (because there are no antigens present when treated with the anti A or anti B antibodies to agglutinate)

List the symptoms of Type 1 diabetes

Fatigue, dizziness, excessive thirst and urination

List the symptoms of Type 2 diabetes

Fatigue, dizziness, excessive thirst and urination

List the treatments for Type 1 diabetes

Insulin shots daily or wear a pump that constantly checks and delivers insulin; careful diet, exercise

List the treatments for Type 2 diabetes

Weight loss, exercise, medications (oral or injection), careful diet

How does Type 1 diabetes work?

The body produces little to no insulin because the beta cells in the pancreas have been damaged (autoimmune, body attacked cells)

How does Type 2 diabetes work?

The cells in the body no longer have as many receptors for insulin to bind with or they are damaged. Usually more insulin than needed is produced to try to compensate

Who suffers from Type 1 diabetes?

Any one can get it, but it is generally genetic in cause. Often discovered prior to adulthood

Who suffers from Type 2 diabetes?

Adults, often middle aged and older. Overweight contributes but does not have to be. Can be genetic as we see it run in families and in certain population groups.

Is sweating when body temperature rises an example of negative or positive feedback?

Negative

Is blood clotting an example of negative or positive feedback?

Positive

Is increased respiration rate when oxygen levels get low in the body an example of negative or positive feedback?

Negative

Give examples of monomers and polymers of lipids.

Fatty acids, glycerol and triglyceride

Give examples of monomers and polymers of carbohydrates.

Monosaccharide and polysaccharide;

Give examples of monomers and polymers of proteins.

Amino acids and proteins

What is osmosis?

Movement of water from high to low concentration

Why are diabetics constantly dehydrated and urinating so often?

Water from the cells and tissues is pulled into the blood due to the high concentration of sugar. This causes the kidneys to process more blood, and pull out more water for urination. All of this causes the patient to feel thirsty and dehydrated.

List three complications of diabetes and the body system it affects.

Nerve damage – nervous system. Kidney damage – urinary system. Heart disease – cardiovascular system.

List three lifestyle changes diabetics can make to manage their disease.

No smoking, healthy diet, more exercise.

What kind of solution doesn't cause any water movement?

Isotonic

What kind of solution causes water to rush OUT of the cell?

Hypertonic

What kind of solution is the cells in blood (in reference to distilled water)?

Hypertonic

What is hyperglycemia?

High blood sugar; caused by diabetes

What is hypoglycemia?

Low blood sugar; can be caused by diabetes

What is the diagnostic test used for diabetes?

Hemoglobin A1C (and glucose tolerance test as well as insulin level measurements)

Briefly describe protein synthesis using DNA, mRNA, nucleus, ribosome, tRNA, amino acid, protein, transcription, translation

DNA is transcribed into mRNA in the nucleus which goes to the ribosomes where the mRNA is translated into codons which are amino acids that build into proteins. The tRNA binds to the codons to help synthesize the growing amino acid chain (protein).

Transcribe this DNA sequence into mRNA, then tRNA, and then translate it into an amino acid sequence: TAC GGG AGA CTA ATT

AUG CCC UCU GAU UAA (mRNA); UAC GGG AGA CUA AUU (tRNA); Met/Pro/Ser/Asp/STOP (amino acid)

This process makes new body cells for repair & replacement.

Mitosis

This process makes identical copies of the parent cell.

Mitosis

This process creates sex cells of sperm and egg.

Meiosis

Each body cell has how many chromosomes?

46 chromosomes

Each gamete has how many chromosomes?

23 chromosomes

Why does sickle cell disease run in families, yet is not present in every generation?

It is a genetic condition passed down from parent to child, but it is recessive so not every person gets it but they may be a carrier for it

If a woman without Best’s disease and a man with two alleles for Best’s disease have a child, what is the chance they will have a child with Best’s disease? (Best's is dominant)

100%

Is this disease dominant or recessive? (Pedigree shows very few shaded shapes and no one in II has it)

Recessive

What is Familial Hypercholesterolemia?

A disorder that causes high LDL levels. It is genetic and a dominant disease. The LDLR gene has a point mutation. The protein that is affected is the one that clears LDL from the bloodstream.

Name the heart structures that carry deoxygenated blood

R atrium, R ventricle, Pulmonary artery, Superior vena cava, inferior vena cava

Name the heart structures that carry oxygenated blood

L atrium, L ventricle, Aorta, Pulmonary veins

What is the pathway blood takes as it passes through the heart?

Deoxygenated blood enters the heart in the superior and inferior vena cavae, right atrium, tricuspid valve, right ventricle, pulmonary artery, lungs, oxygenated blood enters through the pulmonary veins, left atrium, bicuspid/mitral valve, left ventricle, aortic valve, aorta, to the body

What is the role of valves in the heart?

Prevent the backflow of blood.

What is mitral valve prolapse?

When the leaflets of the mitral valve do not close all the way causing regurgitation of blood.

How can mitral valve prolapse lead to left ventricular hypertrophy?

The left ventricle has to pump harder to move the blood through to the aorta and body which can lead to thickening of the LV wall.

What is heart rate?

How many times the heart beats per minute.

What is a normal heart rate?

60-100 bpm

What is blood pressure?

The force exerted by blood on the walls of the arteries when the heart beats. (mmHg)

How is blood pressure measured?

With a sphygmomanometer and stethoscope (if manual)

What is normal blood pressure?

90-120/60-80 mmHg

What are the units of blood pressure?

mmHg

What medication is used to treat high blood pressure?

Diuretics, betablockers, Ca channel blockers (anti-hypertensives)

What does EKG stand for? What does it measure?

Electrocardiogram (also ECG). It measures the electrical conductivity of the heart.

Name the two nodes of the heart and where each is located. Which one is called the “pacemaker”?

Sinoatrial node (SA) is at the top of the R Atrium; Atrioventricular node (AV) is at the bottom of the R atrium near the septum in the middle. The SA node is the pacemaker

What is the conduction pathway of electrical impulses through the heart?

SA node to AV node to L and R bundle branches (in the septum) to the purkinje fibers at the bottom of the ventricles

What are two major functions of cholesterol in the body?

Build and maintain cell membranes and to make hormones

What medication is used to treat cholesterol?

Meds like Lipitor

What is atherosclerosis? How can it affect blood pressure?

The buildup of waxy/fatty substances on the walls of blood vessels. It causes constriction of the arteries and therefore higher pressure to push the blood through them due to the slower flow.