Cell Biology

6 years ago

Onion Cell identify cells

When DNA condenses in prophase can the stained chromosomes be visible with a light microscope. Because the phases are a continuous sequence, late anaphase looks like early telophase. Interphase is characteristically a diagram of a normal cell. The nu

rachelle17 350 4 Replies

6 years ago

When an F1 plant undergoes meiosis, what gamete types will it produce, and in what proportions? Use ...

When an F1 plant undergoes meiosis, what gamete types will it produce, and in what proportions?
Use your understanding of Mendel’s law (or principle) of segregation to label each gamete possibility as “correct” or “incorrect.”

sportspro05 874 1 Reply

6 years ago

Investigate the different parts of the human immune system and explain which cells/products of innat

need answer!!!!!!

vanna2121 896 2 Replies

psyche360

6 years ago

Recombinant DNA Technology

Hello --

I was hoping I could get clarification on a few topics that I've been reading about under the umbrella of Recombinant DNA Technology

1. When two or more sequences join from sources that would otherwise not be capab

grasouli 192 2 Replies

duddy

6 years ago

To reach the brain, the impulse travels through a neuron and across the synapse, respectively, by?

An impulse from one's finger tip travels to the brain for interpretation. To reach the brain, the impulse travels through a neuron and across the synapse, respectively, by

a. hormones and potassium ion transfer
b. electrical mean

chelology 111 1 Reply

6 years ago

The generation of an action potential in the neuron was slower than the 24 m/s that is typical with

The spinal cord has both gray matter (myelin lacking) and white matter (myelin present). A neuron was taken from the spinal cord. The generation of an action potential in the neuron was slower than the 24 m/s that is typical with sensory neurons. Why

chelology 106 1 Reply

6 years ago

Is the the presence of a cell wall affect the shape of a cell?

kindly help me with the question

jong0629 153 1 Reply

6 years ago

A 59-year-old female, with fever of unknown origin, has three sets of blood culture bottles drawn wi

within a 24-hour period. at 24 hours incubation, one anaerobic blood culture bottle reveals the organism seen in the gram stained image provided. the small, white, anaerobic colony grows proves to be catalase, indole-positive, and resistant to SPS. t

rocktober 67 1 Reply

6 years ago

Which one of the following is not a component of each monomer used to make proteins?

Which one of the following is not a component of each monomer used to make proteins?
A) a phosphorous atom, P
B) an amino functional group, NH2
C) a side chain, R
D) a carboxyl group, COOH

Dugg 47 1 Reply

6 years ago

Amino acid side chains (R groups) with what characteristic(s) dissolve best in water?

Amino acid side chains (R groups) with what characteristic(s) dissolve best in water?
A) small sizes and simple structures
B) at least one ring structure
C) polarity or charged structures
D) the presence of sulfur

dracko 72 1 Reply

6 years ago

Why are polymerization reactions endergonic?

Why are polymerization reactions endergonic?
A) They reduce entropy.
B) They release heat, making the reactant monomers move faster.
C) Because the condensation and hydrolysis reactions are equally spontaneous.
D) Because polymers

Dugg 72 1 Reply

mastema

6 years ago

At the pH found in cells (about 7.0), what happens to the carboxyl group on an amino acid?

At the pH found in cells (about 7.0), what happens to the carboxyl group on an amino acid?
A) It acts as a base and gains a proton, giving it a positive charge.
B) It acts as an acid and loses a proton, giving it a negative charge.
C)

pkclary 53 1 Reply

6 years ago

How does the structure of an amino acid enable it to play its most important roles in cells?

How does the structure of an amino acid enable it to play its most important roles in cells?
A) It can serve a wide variety of functions in a cell, because it contains the atoms most commonly found in organisms (C, H, N, and O).
B) Because

pkclary 37 1 Reply

6 years ago

Which of the following involves an increase in entropy?

Which of the following involves an increase in entropy?
A) hydrolysis
B) condensation
C) polymerization
D) chemical evolution

ceybe 50 1 Reply

mastema

6 years ago

In solution, why do hydrolysis reactions occur more readily than condensation reactions?

In solution, why do hydrolysis reactions occur more readily than condensation reactions?
A) Hydrolysis increases entropy and is exothermic.
B) Hydrolysis raises G, or Gibbs free energy.
C) Hydrolysis decreases entropy and is exothermic

Dugg 74 1 Reply

6 years ago

Suppose you discovered a new amino acid. Its R-group contains only hydrogen and carbon atoms. ...

Suppose you discovered a new amino acid. Its R-group contains only hydrogen and carbon atoms. Predict the behavior of this amino acid.
A) It is hydrophobic.
B) It is hydrophilic.
C) Relative to the amino acids found in organisms, its i

ceybe 70 1 Reply

mastema

6 years ago

An isomer of a particular molecule is

An isomer of a particular molecule is
A) a molecule that has the same structure as the target molecule, but a different formula.
B) a molecule that is the same except it has an additional side group.
C) another copy of the same molecul

dracko 61 1 Reply

6 years ago

A peptide bond is (Multiple Choice Question)

A peptide bond is
A) an ionic bond, not a covalent one.
B) a triple covalent bond.
C) a particularly stable, planar covalent bond.
D) a particularly unstable covalent bond.

pkclary 88 1 Reply

6 years ago

Which of the following best describes primary structure in proteins?

Which of the following best describes primary structure in proteins?
A) It is the number of amino acids present in the complete protein.
B) It is the number of peptide bonds in the complete protein.
C) It is the sequence of amino acids

pkclary 52 1 Reply

6 years ago

You are studying a protein that is shaped like a doughnut. The shape is a function of which level(s) ...

You are studying a protein that is shaped like a doughnut. The shape is a function of which level(s) of protein structure?
A) primary only
B) secondary only
C) tertiary only
D) secondary and tertiary only
E) primary, secondar

Dugg 78 1 Reply

6 years ago

An enzyme has a total of four active sites. When you denature the molecule and study its ...

An enzyme has a total of four active sites. When you denature the molecule and study its composition, you find that each active site occurs on a different polypeptide. Which of the following hypotheses does this observation support?
A) The enzym

dracko 55 1 Reply

6 years ago

You've just sequenced a new protein found in mice and observe that sulfur-containing cysteine ...

You've just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. What is the significance of this finding?
A) Cysteine residues are required for the formation of α-helices an

dracko 41 1 Reply

6 years ago

Recent technological advances have made it more feasible than ever to work out the three-dimensional ...

Recent technological advances have made it more feasible than ever to work out the three-dimensional structure of proteins. There is intense interest in this research field, called structural biology. Why?
A) Understanding structure should help

pkclary 78 1 Reply

6 years ago

What type of interaction is directly responsible for the formation of secondary structure?

What type of interaction is directly responsible for the formation of secondary structure?
A) peptide bonds between adjacent amino acids
B) peptide bonds between nonadjacent amino acids
C) hydrogen bonds between sections of the polypep

dracko 45 1 Reply

6 years ago

A series of hydrophobic side chains will congregate together as a protein folds in an aqueous ...

A series of hydrophobic side chains will congregate together as a protein folds in an aqueous solution and be stabilized by
A) disulfide bonds.
B) van der Waals interaction.
C) hydrogen bonds.
D) quaternary structure bonds.

pkclary 111 1 Reply

6 years ago

If the primary structure of a protein is incorrect

If the primary structure of a protein is incorrect
A) the secondary structure will be correct.
B) the tertiary structure will be correct.
C) any quaternary structure will be correct.
D) any higher-level folding of the protein will

pkclary 117 1 Reply

6 years ago

You have isolated a previously unstudied protein, identified its complete structure in detail, and ...

You have isolated a previously unstudied protein, identified its complete structure in detail, and determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites. One of these is large, apparently the bonding sit

pkclary 90 1 Reply

6 years ago

Which of the following is not true when comparing an uncatalyzed reaction to the same reaction with ...

Which of the following is not true when comparing an uncatalyzed reaction to the same reaction with a catalyst?
A) The catalyzed reaction will be faster.
B) The catalyzed reaction will have a different ∆G.
C) The catalyzed reaction wil

ceybe 55 1 Reply

6 years ago

Which of the following would be an example of a cofactor?

Which of the following would be an example of a cofactor?
A) an enzyme active site that contains an α-helix
B) the nonprotein heme group in a hemoglobin molecule
C) the disulfide bridge that forms between cysteine residues
D) a β-

pkclary 56 1 Reply

6 years ago

In cells, the activity of enzymes is often regulated by other molecules. Why is this necessary?

In cells, the activity of enzymes is often regulated by other molecules. Why is this necessary?
A) because all enzymes require some help from another molecule to function correctly
B) because other molecules are necessary to prevent enzymes

dracko 63 1 Reply

6 years ago

You've discovered an enzyme that can catalyze two different chemical reactions. Which of the ...

You've discovered an enzyme that can catalyze two different chemical reactions. Which of the following is most likely to be correct?
A) The enzyme contains both α-helices and β-pleated sheets.
B) The enzyme is subject to both competiti

ceybe 64 1 Reply

6 years ago

HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV called ...

HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV called protease. Once the enzyme's structure was known, researchers began looking for drugs that would fit into the active site and block it. If this st

pkclary 40 1 Reply

6 years ago

Consider the HIV enzyme called protease. The amino acid residues at the active site are highly ...

Consider the HIV enzyme called protease. The amino acid residues at the active site are highly hydrophobic. In designing a drug that would bind to the active site and jam it, researchers should use which type of molecule?
A) hydrophobic
B)

ceybe 53 1 Reply

6 years ago

When, and by whom, was the lock-and-key model of enzyme specificity developed?

When, and by whom, was the lock-and-key model of enzyme specificity developed?
A) 1894 by Fischer
B) 1894 by Miller
C) 1936 by Fischer
D) 1956 by Fischer
E) 1974 by Haldane and Oparin

Dugg 38 1 Reply

6 years ago

Which one of the following is not a component of each monomer used to make proteins?

Which one of the following is not a component of each monomer used to make proteins?
A) an iron atom, Fe
B) an amino functional group, NH2
C) a side chain, R
D) a carboxyl group, COOH

Dugg 35 1 Reply

6 years ago

How many times does the protein in Figure 3.1 cross the cell membrane?

How many times does the protein in Figure 3.1 cross the cell membrane?
A) 1
B) 3
C) 4
D) 7

dracko 45 1 Reply

6 years ago

If you were reading off the sequence of amino acids in Figure 3.1 to a biologist friend, what should ...

If you were reading off the sequence of amino acids in Figure 3.1 to a biologist friend, what should the first three letters be?
A) M-N-G
B) A-P-A
C) It doesn't matter, since the protein has no polarity or directionality.

Dugg 56 1 Reply

6 years ago

Identify the location of the disulfide bond in Figure 3.1. What is the name of the amino acids that ...

Identify the location of the disulfide bond in Figure 3.1. What is the name of the amino acids that are forming this bond?
A) cytosine
B) aspartic acid
C) cysteine
D) glycine

dracko 39 1 Reply