-which of the following is NOT true? A) enzyes have a specific shape B) enzymes
ID: 92988 • Letter: #
Question
-which of the following is NOT true?
A) enzyes have a specific shape
B) enzymes are specific for the reaction they catalyze
C) enzymes are catalysts that make chemical reactions occur faster
D) enzymes are used up in a chemical reaction
E) Enzymes can be denatured and lose their function
-An enzyme may lose its ability to function because of :
A) excessively high temperatures
B) presence of an enzyme inhibitor that binds to its active site.
C) an environment that is too acidic
D) a change in its three dimensional structure and shape
E) All of the above
-what are the two reactants that are brought together by an anzyme in the browing reaction when fruits and vegetables are bruised or cut open?
A) benzoquinone + water
B) catechol + oxygen
-The interior of the plasma membranes is __________ which prevents the passage of ions and most polar nolecules.
A) Isotonic
B) Hydrophilic
C) hydrophobic
D) slightly charged
-which of the following would be an example of osmosis?
A) glucose is trasnported into cells with a carrier protein
B) Carbon dioxide moves out of cells to the blood and into the lungs.
C) A vesicles containing a hormone fuses with a plasma membrane ro export it.
D) Potassium ions are pumed against the concentration gradient using a carrier protein and ATP.
E) Water moves inside of cells that are in a hypotonic solution.
Explanation / Answer
1. Answer- option D.
Explanation:- Enzymes act as catalyst and they do not themselves take part in the reaction. Therefore, enzymes are not used up in the chemical reaction.
2. Answer:- Option E
Explanation:- Enzymes function optimally in specific range of temperature and pH. Though enzymes functioning at higher temperature and pH are present, they are very few. Average enzymes have optimal temperature and pH range, which is not extreme. Also, enzyme inhibitors inhibit enzyme action. The structure and conformation of enzyme makes it specific and functional. Thus all the factors mentioned in the options of the question render the enzyme dysfunctional.
3. Answer:- Option B
Explanation:- Enzymatic browning is one of the most important reactions that takes place in most fruits and vegetables. Catechol oxidase is an enzyme involved in this reaction. The enzymatic reaction leads to production of two ortho-quinones and 2 molecules of water from two molecules of catechol and one molecule of dioxygen.
4. Answer-Option C
Explanation:- The fundamental structure of the membrane is the phospholipid bilayer. Phospholipids are characteristically hydrophilic ("water-loving") at their phosphate ends and hydrophobic ("water-fearing") along their lipid tail regions. In each layer of a plasma membrane, the hydrophobic lipid tails are oriented inwards and the hydrophilic phosphate groups are aligned so they face outwards, either toward the aqueous cytosol of the cell or the outside environment. This phospholipids helps in prevention transport of ions and most polar molecules.
5. Answer- Option E
Explanation:-Osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one. When cells are in the hypotonic solution, water will pass from the hypotonic solution (less concentrated) to the cells (high concentrated).
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.