1. why does olive oil have a lower melting point than butter fat?
2. how does LDL differ from HDL's
3. In a helix, how does bond occur between the amino acids in the peptide bond?
4. what is the difference in bonding between an alpha helix and a Beta plated sheet?
5. if serine were replaced by valine in a protein how would the tertiary stucture be affected?
6.(a) How does an enzyme speed up the reaction of a substrate
(b) after the products have formed what happens to the enzymes?
7. How does a lactase make the reaction go faster.
In: Chemistry
11. Repeated exposure to hot environments when combined with exercise improves exercise capacity, with less discomfort upon subsequent heat exposure. One thing that changes is that a person begins sweating sooner and they sweat more (nearly double). Sweating sooner represents what type of change?
a) decreased threshold
b) increased threshold
c) decreased set point.
d) increased set point
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12.Which statement(s) about control strategies is/are incorrect? Choose any that apply.
a) An advantage of a feedforward system is that it allows the body to anticipate a change, or prepare for something to happen.
b) A disadvantage of a feedforward system is it doesn’t allow you to respond to an unexpected change.
c) An advantage of a positive feedback system is allows for rapid changes to a regulated variable.
d) A disadvantage of a positive feedback system is that it is not homeostatic. e) A disadvantage of a negative feedback system is it requires some outside event to stop the response.
f) All of the above are correct.
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13. Which of the following compounds is a carbohydrate? Choose any that apply. a) C5H10O5 b) C6H12O6NS c) C3H6O314. 14. Water is polar; organic solvents (for ex., gasoline, ether, carbon tetrachloride and benzene) are nonpolar. A substance is found to dissolve in organic solvents but not in the water. Is this substance most likely polar or nonpolar, or both?
a) both
b) nonpolar
c) polar
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15. An 18-year-old girl presents with a lack of secondary sexual characteristics, such as age-appropriate pubic hair growth and breast development. Her history reveals she has never started menses. She is diagnosed with a deficiency. The levels of various steroid hormones in her serum are found to be abnormal. Which of the following is she most likely lacking or does she most likely have very low levels of?
a) acetyl CoA
b) cholesterol
c) fatty acids
d) glucose
e) oleic acid
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18. There is an amino acid transporter that only transports acidic amino acids, another that transports basic amino acids, and a third that transports neutral amino acids. This is an example of which protein characteristic?
a) affinity
b) saturation
c) specificity
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20. Many people die each year from ingesting antifreeze solutions. Antifreeze contains ethylene glycol, which the human body converts to oxalic acid in the presence of the enzyme alcohol dehydrogenase. Oxalic acid exists in crystalline form and these crystals can severely damage kidneys. Ethanol is administered to victims with ethylene glycol poisoning because ethanol binds to the active site of alcohol dehydrogenase, inhibiting the formation of oxalate crystals. How would you classify ethanol in this scenario?
a) allometric inhibitor of ethylene glycol
b) allosteric inhibitor of ethylene glycol
c) cofactor of ethylene glycol
d) competitive inhibitor of ethylene glycol
e) covalent inhibitor of ethylene glycol
In: Anatomy and Physiology
A gene is 8,001 nucleotides in length. Studies of this gene show that it encodes a protein only 400 amino acids long – far shorter than the 2,667 amino acids that were expected. This is best explained by the fact:
nucleotides often break off and are lost during the transcription process.
the genetic code is ambiguous (unclear).
in some cases, many nucleotides are used to encode a single amino acid.
many of the 8,001 nucleotides of the gene are ultimately noncoding.
In: Biology
In: Anatomy and Physiology
Which statement is FALSE of the genetic code?
a) it contains a list of codons and the amino acids they code for which combine together to form proteins
b) a total of 20 amino acids are coded for by more than 20 codons
c) a codon 'word' consists of three nucleotides, and each codon codes for one amino acid
d) different codons can code for the same amino acid, if they share the same first two nucleotides in the codon
e) the third nucleotide in the codon needs to be precise for the correct amino acid according to the wobble hypothesis
What is natural hybridization between species?
a) the process of producing DNA clones by inserting the genes from one species into another
b) the process of individuals from dissimilar groups mating and forming viable offspring
c) the process of individuals that are genetically identical mating and creating genetically variable offspring
d) the process of amplifying small regions of DNA into millions of copies within a short period of time
e) none of these are true
After the process of meiosis is completed to form sperm and egg cells, they come together to created fertilized human cell which is..
a) diploid
b) haploid
c) a zygote
d) triploid
e) both A & C
What is NOT a physical characteristic of DNA?
a) double helix
b) antiparallel
c) complimentary base pairing
d) single stranded
e) has thymine bases
What is the direction of the flow of information within cells?
a) proteins, RNA, DNA
b) DNA, proteins, RNA
c) DNA, RNA, proteins
d) RNA, DNA, proteins
What is the difference between restriction enzymes (REs) and polymerase chain reaction (PCR)?
a) REs are used to create millions of copies of DNA, PCR is involved in inserting DNA from one place to another
b) REs are used in cell regeneration, PCR is used in inserting fragments into bacterial plasmids
c) REs help cut DNA into smaller fragments, PCR is used to transfer foreign DNA from viruses
d) RE's cut DNA at specific sequences of nucleotides, PCR is used to amplify a certain section of DNA into millions of copies
e) RE's use the Cas-9 enzyme, PCR uses the CRISPR enzyme
In fruit flies, eye color is a sex-linked gene, where red color is dominant to the mutation causing white eyes. If a red-eyed male mated with a white-eyed female, what will the phenotypes of the offspring be?
a) all of the females will have red eyes, all the males will have white
b) all of the females will have white eyes, all of the males with have red
c) all of the offspring will have red eyes
d) all of the offspring will have white eyes
Which is TRUE of a DNA mutation?
a) is a change in the nucleotide sequence
b) always results in a change in the protein
c) may change the protein IF the change in nucleotide sequence occurs inside of a gene AND changes the amino acid of a codon
d) all of the above
e) A & C only
True or False: DNA methylation is a type of epigenetic change which can alter gene expression, even though there is no mutation in the genetic sequence itself.
In: Biology
Amino acids can have very specific properties. Some specific properties of interest are size (small/medium/large), If its is bulky/rigid/flexible, if it is hydrophilic or hydrophobic and if is positively or negatively charged.
1A. For the properies of size, bulk/rigidity/flexibility, hydrophilic or hydrophobic and positive or negatively charged, provide detailed descriptions of what we woud look for in the "R" group of the amino acid to decide what traits give it these properties. (10 points)
1B. For each of the twenty amino acids, name if it is big/medium/small, bulky/rigid/flexible, hydrophilic or hydrophobic and positive or negatively charged.
If any of the twenty amino acids you describe do not follow the trend that you provided in part A, provide a detailed explanation for why. (30 points)
In: Biology
Answer the following questions (a through f) based upon a peptide sequence with the following amino acids (one-letter symbols are given): EHSGLR
(a) What are the full names and three-letter abbreviations of the amino acids?
(b) At physiological pH, what is the best description of the chemical properties of the side chains(R groups)? (Hint: Select between nonpolar, polar uncharged, positively charged, negatively charged)
(c) Draw the structure of this peptide at pH 7.0.
(d) What is the net charge of the molecule at pH 3, 8, and 11? (Use pKa values for side chains and terminal amino and carboxyl groups as given in Table 3–1.)
(e) Estimate the pI for this peptide.
(f) What type of intermolecular force could the side chains form with water? (Note that these are interactions are with water, not with other amino acids.)
In: Chemistry
If the amino acid 24 was mutated from a glycine to an arginine, and the binding assay results were negative, what would you conclude from these results about the role of this amino acid in binding to the ligand? (1 point)
Explain in detail and also suggest other amino acid changes that would help understand these results further.
In: Biology
Description: Unnatural amino acid mutagenesis might be one of the most groundbreaking achievements in modern biochemistry. This process allows for the incorporation of amino acids not coded for by the body (one's different from the 20 amino acids you studied in this course). This process allows scientists to use amino acids with different functional groups not found in nature.
Instructions: You will investigate how unnatural amino acid mutagenesis works. Take time to examine what changes needed to be made to the tRNA to allow for an unnatural amino acid to be used instead of the native substrate. Also focus on what codons are used to recognize the modified tRNA. How many different codons are there that can be used? What are they called? Please cite any sources used in this discussion (should contain 5-10 sources). This paper should be around 1-3 pages and cover a good deal of detail on how this process works. If you would like to submit early, I would be more than happy to look over it and return it with some suggestions.
In: Biology
Common proteins are polymers of 20 different amino acids. How many amino acids are necessary for a protein polymer to have at least as many possible different sequences as there are atoms in the Universe?
(There are about 2 × 1056 moles of atoms in the Universe.)
*Note - The answer is a mathmatical answer. I need an explanation of the math behind this problem.
In: Biology