BME 1020 Exam 1|65 Questions with Verified Answers
Define the term "biomedical engineering" - CORRECT ANSWER The application of engineering techniques
... [Show More] to the understanding of biological systems, practice of medicine, development of therapeutic technologies
Distinguish Biomedical engineering from closely associated fields - CORRECT ANSWER Biomedical engineering is closely associated to disciplines such as physics, chemistry, material science, mechanical engineering, computer science, etc. It is different from those fields as it combines them and applies to biomedical principles rather than thinking about them separately; in BME, these concepts will always be tied back to biology and medicine .
List five technical subspecialties of biomedical engineering. - CORRECT ANSWER Biomaterials, Biomechanics, Bioinformatics, Bioinstrumentation, Biomedical Imaging
What are three common entry level jobs for biomedical engineers with a BS degree? - CORRECT ANSWER Product Design Engineer, Quality Engineer, Regulatory Affairs Associate
What is meant by the term "Tissue Engineering"? - CORRECT ANSWER The practice of combining scaffolds, cells, and biologically active molecules into functional tissues.
What is meant by the term "Personalized Medicine"? - CORRECT ANSWER The practice of tailoring medical decisions, practices, interventions and/or products to the individual patient based on relevant biomarkers from that patient
How are advances in imaging driving improved healthcare? - CORRECT ANSWER Improved surgical techniques, Easier diagnosis, etc
(A) List the most common elements found in the human body and (B) the four classes of biopolymers that they comprise. - CORRECT ANSWER (A)H,C,N,O,Na,Mg,P,S,Cl,K,Ca,Fe,I
(B) The four classes of biopolymers:
-lipids (fats)
-polysaccharides (sugars and carbohydrates)
-nucleic acids (DNA and RNA)
-proteins (amino acids)
[DIAGRAM] Draw and label a schematic diagram representing 10 important systems that are vital to human life. Be sure to indicate which systems interact with each other. - CORRECT ANSWER
(A) List the various subcompartments where water is distributed in the human body and (B) their approximate percentage of total body water. - CORRECT ANSWER 1. 40% intracellular fluid
2. 20% extracellular fluid
3. 15% interstitial fluid
4. 5% intravascular fluid
(A) Using a common set of small molecules as examples explain the difference between polar and non-polar molecules. (B) Why is polarity important to living systems? - CORRECT ANSWER (A) water (h2o): has a net dipole moment
methane (ch4): non polar, does not have net-dipole moment
-polar molecules have opposing charges, soluble in polar substances (hydrophilic); nonpolar molecules have an equal charge, soluble in non-polar substances (hydrophobic)
(B) polarity is critical to living systems because it allows for acid/base balances in the body, various chemical reactions, and acts as a hydrophilic coating and bulk materials in many tissues/organs
What is meant by the term "polymer". - CORRECT ANSWER poly=many
meros=parts
a polymer is a macromolecule; they exist in network of entangles or cross-linked chains of repeating monomers (which are long repeating chain molecules)
(A) List the four major types of biological polymers (biopolymers) and (B) provide a simple chemical or structural representation of each. - CORRECT ANSWER (A)
1. Lipids (Fats)
2. Polysaccharides (Sugars and Carbohydrates)
3. Nucleic Acids (DNA and RNA)
4. Proteins (Amino Acids)
Describe what is meant by the term "condensation reaction" and provide an example. - CORRECT ANSWER Two molecules are combined in a reaction with small molecule as a by-product, often this product is water, but not always. Example: condensations of two amino acids to give a peptide bond with water as the by-product.
(A) What is a polysaccharide? (B) Where are they commonly found in the human body? (C) What role(s) do they serve? - CORRECT ANSWER (A) A polysaccharide is a sugar polymer (ex, cellulose or glycogen)
(B) Glycogens found in the liver; a lot of polysaccharides are found in muscle tissue
(C) Polysaccharides regulate the hydration of tissue which affects the mechanical and structural properties of the working systems of the body
What is the general chemical structure of a lipid molecule? - CORRECT ANSWER CH2-CH2
-a lipid molecule will typically either be:
1. straight line/saturated (contain NO double bonds)
2. cis-saturated
3. trans-saturated
4. unsaturated
What molecules are found in all cell membranes and how are they organized, that is, which end of the molecule faces the extracellular fluid (ECF) and which end is buried inside the bilayer? - CORRECT ANSWER 1. molecules existing IN cell membrane: HYDROPHOBIC ones, meaning they are non-polar
2. Cell membranes consist of a phospholipid bilayer, with the hydrophilic head facing the outside of the membrane, and hydrophobic tails inside
Describe two roles of cell membranes - CORRECT ANSWER 1. Facilitate transportation in and out of the cell
2. Allow for interactions between cells
What is the difference between an unsaturated, cis-saturated, trans saturated, and saturated lipid.? - CORRECT ANSWER (A) Saturated fats are carbon chains in which every carbon has the maximum amount of carbons it can have
(B) Cis-unsaturated fats have a double bond in the chain, in which both excess hydrogens are on the same side of the chain
(C) Trans-unsaturated fats have a double bond in the chain in which both hydrogens are on opposite sides of the chain
(D) Unsaturated fat: a type of fat containing a high proportion of fatty acid molecules with at least one double bond
Provide three differences between RNA and DNA. - CORRECT ANSWER DNA (deoxyribonucleic acid):
1. No hydroxyl on C2
2. Double helix (2 paired DNA molecules wrapped together but running in opposite directions
3. Stores genetic information in the cell's nucleus and the mitochondria (genome)
RNA (ribonucleic acid):
1. C2 is hydroxylated
2. RNA is single-stranded (still has structure though)
3. RNA transfers genetic information from the nucleus to the cytoplasm, where it is translated into protein at the ribosome
Describe the basic structure of a nucleotide. - CORRECT ANSWER A nucleotide consists of a sugar (ribose or deoxyribose) bonded to a phosphate and a nitrogenous base
(A) Describe what is meant by the term "base pairing". (B) Describe the base pairing rules for DNA and RNA. (C) Describe 2 phenomena that stabilize base pairing. - CORRECT ANSWER (A) Base pairing: Each base (A,T,G,C) corresponds to another based on the structure of the base and the helical strand overall
(B) Base pairing rules for DNA and RNA :
DNA: A-T, G-C
RNA: A-U, G-C
(C) 2 phenomena that stabilize base pairing:
1. Hydrogen bonding
2. Pi-Stacking
If given a sequence of DNA be able to give the complementary strand of DNA and RNA: - CORRECT ANSWER DNA: G-C, A-T, T-A
-G-C have a place for three hydrogen bonds, T-A have a place for two hydrogen bonds
RNA: G-C, A-U
-Purine ALWAYS pairs with a pyrimidine
Describe how DNA is packaged in the nucleus of somatic cells (6 steps). - CORRECT ANSWER The DNA is packaged into 23 individual molecules (23 pairs of somatic cells) called chromosomes.
1. It starts as DNA
2. Turns into nucleosomes
3. turns into chromatin
4. Then chromatin loops
5. Then condensed chromatin loops
6. and finally, a chromosome
(A) What is meant by a Karyotype and (B) how is it used in medicine? - CORRECT ANSWER (A) A karyotype is a chromosome count of an organism; humans have 23 chromosomes. 22 of them are autosomal, 1 is allosomal
(B) Karyotypes are used in medicine for prenatal karyotyping to check for chromosome abnormalities
(aneuploidy is having an abnormal # of chromosomes which relates to down syndrome)
How is a germ cell different from a somatic cell? - CORRECT ANSWER (A) Germ cells (sperm and egg cells) only have ONE set of chromosomes
(B) Somatic cells have TWO sets of chromosomes
What is meant by the term "genome"? - CORRECT ANSWER The entire set of genetic material in an organism; the regions within the genetic material of an organism that are responsible for gene coding
Besides the nucleus, what other organelle contains its own DNA? Describe how this is theorized to have happened. - CORRECT ANSWER (A) The mitochondria (mtDNA) contains its own DNA; only comes from the mother (rare cases can come from the father)
(B) Endosymbiotic theory: the theory that mitochondria were prokaryotes that formed a symbiotic relationship with eukaryotic cells
(A) Describe what is meant by the term DNA replication and (B) describe why is it important in biological systems? - CORRECT ANSWER (A) DNA replication is the creation/duplication of DNA using the existing DNA as a template; this results in two identical copies of DNA both with one parental strand and one new strand
(B) DNA replication is important in biological systems because it allows cells to replicate which in turn allows organisms to grow/form and repair themselves when damaged or worn down
[DIAGRAM] Provide a diagram of the DNA replication machinery.
1. double helicase unwound by ___ and ___
2. ____ produces leading strand copy
3. another ____ binds to the ____ strand
4. this enzyme makes discontinuous segments called ____ _____ before ____ _____ joins them back together - CORRECT ANSWER Steps of DNA replication:
1. the double helicase is unwound by a helicase and topoisomerase
2. next, one DNA polymerase produces the leading strand copy
3. another DNA polymerase binds to the lagging strand
4. this enzyme makes discontinuous segments (called Okazaki fragments) before DNA ligase joins them together
List the names and functions of the enzymes involved in the replication of DNA.
(8 total) - CORRECT ANSWER 1. Topoisomerase
2. DNA helicase
3. SSB proteins (single-strand binding)
4. DNA polymerase
5. Primase
6. RNA primer
7. Exonuclease
8. DNA ligase
With regards to the field of biology what is the "Central Dogma"? - CORRECT ANSWER (Biology) Central Dogma: DNA guides RNA synthesis, RNA guides protein synthesis, so DNA-->RNA-->Protein
Compare and contrast the terms transcription and translation. In your answer describe the starting source of information, where the process occurs, the major enzyme used for the process, and what the end product is. - CORRECT ANSWER 1. Transcription:
Purpose: make RNA copies of gene sequence
Definition: make mRNA strand from DNA
Process: mRNA molecule leaves cell nucleus, enters the cytoplasm, then directs the synthesis of the protein which it encodes
Where: nuclues
End Product: copies of RNA
IMPORTANT:
-Performed by RNA polymerase
-happens when a strand of DNA
undergoes the process of creating RNA
-RNA polymerized in 5' to 3' direction
-elongation proceeds until terminator sequence
2. Translation:
Purpose: to synthesize proteins
Definition: assembling of amino acids into polypeptide chains by the ribosomes, following instructions of mRNA
Process: translating the sequence of an mRNA molecule to a sequence of amino acids during protein synthesis
Where: cytoplasm
End Product: proteins (yay!)
IMPORTANT
-translation of an mRNA molecule by the ribosome occurs in three stages: initiation, elongation, and termination
-start codon recognized, and at 5' cap of the mRNA the ribosome subunit binds
List the 3 most common types of RNA and what they are used for - CORRECT ANSWER 1. Messenger RNA (mRNA): carrier of the genetic code out of the nucleus
2. Ribosomal RNA (rRNA): help to stabilize the structure of the mRNA and tRNA in the ribosome
3. Transfer RNA (tRNA): takes specific single amino acids into the ribosome to help build the new protein
[DIAGRAM] Provide a diagram that outlines each step in the central dogma of biology. Be sure to place each step in the appropriate compartment of the cell. - CORRECT ANSWER
What is meant by the term "RNA processing." - CORRECT ANSWER (A) RNA Processing: The process of removing introns and rejoining exons of the mRNA to convert genetic info to proteins to determine the cell's structure and function.
What is a ribosome made of and what is its function? - CORRECT ANSWER (A) A ribosome is made of complexes of RNAs and ribosomal proteins (called ribonucleoproteins or ribozymes)
(B) The function of the ribosome is to read the 3 codons on the mRNA and then signal the tRNA to pair certain correlating amino acids for the ribosome to bind together to create certain proteins
Describe the 4 levels of protein structure - CORRECT ANSWER 1. Primary: the sequence of amino acids forms the polypeptide chain
2. Secondary: the primary chain forms spirals (the alpha helix) and sheets (beta sheets)
3. Tertiary: superimposed on the secondary structure; alpha helices and/or beta sheets are folded up to form a compact globular molecule held together by intramolecular bonds (IMFs)
4. Quaternary structure: two or more polypeptide chains, with their own tertiary structure, combine to form functional proteins
Describe why pH is important in biological processes involving protein function? (2 reasons) - CORRECT ANSWER 1. pH affects the folding of proteins by affecting acid/base as well as polar/non-polar interactions
2. Significant changes of the pH can cause denaturing
What 4 methods can scientist use to denature proteins? - CORRECT ANSWER 1.Adding heat to a strong base
2. Creating a change in pH
3. Creating contact with hydrophobic medical tools/devices
4. Creating a change in salt concentration
List four different functions of proteins in living cells. - CORRECT ANSWER 1. Structural support (inside, outside, and between cells)
2. Allows for communication between cells and inside cells (soluble-diffusion and convection mediated, hepatic-touch mediated)
3. Catalyzing reactions
4. Storage and transportation of other biomolecules
What is meant by the term "post translational modification" of proteins? - CORRECT ANSWER A modification that occurs right after the protein is created; some examples include additional folding, cutting/removing parts from the amino acid chain, glycosylation-addition sugars, phosphorylation-addition of phosphate, and the addition of an acetal group
What is the difference between the term "genome" and the term "proteome"?
(HINT: genome 3 reasons, proteome 5 reasons) - CORRECT ANSWER Genome:
1. 20,000-30,000 genes that make up a human's genetic information
2. Somatic cells contain a COMPLETE genome
3. doesn't change over time
Proteome:
-over 30,000 genes that make up all of the proteins in a human's body
-Somatic cells DO NOT contain the full proteome, only parts of it
-More bc of post translations modification and alternative splicing
-individual cell types express only portions of the full proteome at a given time
-protein expression within a given time is very dynamic
[DIAGRAM] Provide a graph to describe the mechanism for enzyme action from the point of view of 'activation energy'. - CORRECT ANSWER
[DIAGRAM] Provide a diagram to describe the mechanism of enzyme action from a structural standpoint (i.e. describe what is happening to the structure of the enzyme and substrate). - CORRECT ANSWER
Exact Percentages of Water Distribution in the Human Body
1. Brain
2. Skin
3. Heart
4. Lungs
5. Liver
6. Spleen
7. Kidneys
8. Intestine
9. Adipose tissue
10. Muscle
11. Bone - CORRECT ANSWER Brain - 75% Water
Skin - 72% Water
Blood, Kidneys - 83% Water
Heart, Lungs - 79% Water
Liver - 68% Water
Spleen, Muslce - 76% Water
Intestine - 75% Water
Adipose Tissue - 10% Water - This is important because adipose tissue is body fat, which shows how fat has low water content
Bone - 22% Water
DNA and RNA monomers are - CORRECT ANSWER nucleotides
Proteins monomers are - CORRECT ANSWER amino acids
What proteins/enzyme catalyze these polymerization reactions?
1. DNA
2. RNA
3. Proteins - CORRECT ANSWER 1. DNA polymerase
2. RNA polymerase
3. Ribosomes
Toposiomerase - CORRECT ANSWER Relaxes the DNA from super-coiled nature
DNA Helicase - CORRECT ANSWER Aka "destabilizing enzyme," unwinds DNA double helix at replication fork
SSB proteins (single-strand binding proteins) - CORRECT ANSWER bind to single strand DNA and prevent double helix from re-annealing (rejoining) after the DNA helicase unwinds it
DNA polymerase - CORRECT ANSWER Builds new duplex DNA strand by adding nucleotides in the 5' to 3' direction; proof reads/corrects errors. MANY DIFFERENT TYPES OF DNA POLYMERASE, they perform different functions in different types of cells
Primase - CORRECT ANSWER Provides starting point of RNA (or DNA) for DNA polymerase to begin synthesis of the new DNA strand
RNA Primer - CORRECT ANSWER Added by primase as a place holder; happens on both leading and lagging strands
Exonuclease - CORRECT ANSWER Removes RNA primers from both strands
DNA Ligase - CORRECT ANSWER Re-anneals (rejoins) the semi-conservative strands and Okazaki (OK-azaki) fragments
Lipid monomer - CORRECT ANSWER methyl group
polysaccharide monomer - CORRECT ANSWER vast array of monosaccharides
nucleic acids - CORRECT ANSWER 5 primary nucleotides
proteins - CORRECT ANSWER 20 amino acids
Something that always happens between a purine and pyrimidine - CORRECT ANSWER purine: too long
pyrimidine (too short)
How does transcription work? - CORRECT ANSWER Only 1 DNA strand acts like a template. RNA Polymerase binds the DNA at the promoter, reads the gene & attaches complementary RNA nucleotides, forming the new mRNA.
How does translation work? (6 main steps) - CORRECT ANSWER 1. mRNA leaves nucleus and goes to a ribosome
2. Ribosomes "read" mRNA as codons
3. Individual tRNAs match the codon with their anticodon
4. Amino Acids are attached to the growing protein chain with a peptide bond
5. The ribosome moves down the mRNA strand by 3 nucleotides, to the next codon
6. A new tRNA arrives, and the cycle continues until a stopping point is reached
Describe 3 processing steps that occur to mRNA before it is translated into protein. - CORRECT ANSWER 1. Splicing - The removal of introns and joining of exons together to make the final code
2. 5' - Modified GTP (guanosine triphosphate) added to the 5' end, recognition site for the ribosomes, protects mRNA from degradation (CAPPING)
3. 3' Pol(A) Tail - 150+ Adenine nucleotides added to the 3' end, promotes export from the nucleus, protects the mRNA from degradation (TAILING) [Show Less]