Chapter 3 Questions Flashcards
L-dopa is used to treat _____.
Parkinson’s disease
What kind of effect does R-dopa have on Parkinson’s disease
Nothing
Structural isomers
differ in the covalent partnerships between their atoms.
Geometric isomers
vary in arrangement of atoms around a double bond.
Enantiomers
are molecules that are mirror images of each other, like left and right hands.
Enantiomers are molecules that _____.
are mirror images
Which statement helps most to explain why life is based on carbon compounds?
A) C is very abundant in non-living nature.
B) C-C bonds are as strong as C-O bonds.
C) Each C atom makes three covalent bonds.
D) C makes strong bonds with O
E) All of the above.
B) C-C bonds are as strong as C-O bonds.
Carbon skeletons may be arranged in rings.
TRUE
Carbon skeletons only contain double bonds.
FALSE
Carbon skeletons are always linear and never branched.
FALSE
The length of carbon skeletons is always the same; it is the attachments that differentiate molecules
FALSE
Amino Group
NH2
Carbonyl Group
CO
Hydroxyl Group
HO
Carboxyl Group
CO2H
Sulfhydryl Group
HS
Phosphate Group
PO4
Which of the following would bind to a sweet receptor most tightly? grapes malted milk shake milk table sugar
grapes
About Sucrose
(a) It’s a disaccharide.
(b) It contains glucose.
(c) It’s table sugar.
Polymers that contain sugars …
(a) may store hereditary information.
(b) may store energy.
(c) may protect cells.
Unmodified sugars (those with the formula Cn H2n On ) can have …
- H covalently bound to the C of a C=O group.
2. the formula C3H6O3
A molecule has the formula Cn H2n On . What else does it need to be an unmodified monosaccharide?
O bound to every C
What is the LEAST that two molecules can differ, and still be called different kinds of sugars?
The orientation of an OH group differs.
The alpha and beta forms of glucose, found in starch and cellulose, differ in …
how one of the -OH groups is oriented.
What happens when glucose forms a ring?
The molecule loses its carbonyl group.
Sugar can be found in …
(a) ATP.
(b) DNA.
(c) starch.
A sugar can have …
H covalently bound to the C of a C=O group.
A molecule with the formula C6H12O6 is _____.
possibly glucose or fructose
An organic molecule can have many functional groups.
True
Organic molecules are only made by living organisms.
False
Some organic molecules contain carbon atoms; others do not.
False
Polymers are always made of monomers.
True
Polymers’ synthesis generally consumes water.
False
Polymers are always made by condensation reactions.
False
Polymers are often made by a hydrolysis process.
False
The organic molecule called DNA is an example of ….
a polymer made of nucleotides.
Dehydration reactions _____. They do so by _____.
link monomers to form a polymer … removing a water molecule
The reaction that joins two monomers to form a polymer is known as a _____ reaction. The molecule of water formed is due to the interaction between _____ and a hydrogen ion.
dehydration … a hydroxyl group
What does the term amino acid signify about the structure of the molecule?
It consists of an amino group and a carboxyl group.
Glycogen is _____.
a polysaccharide found in animals
glucose + glucose —> _____ by _____.
maltose + water … dehydration synthesis
Which of these is a source of lactose? starch sugar beets milk sugar cane potatoes
milk
Which of these is a polysaccharide? lactose sucrose glucose cellulose galactose
cellulose
_____ is the most abundant organic compound on Earth.
Cellulose
Cellulose is …
made with glucose that has the beta ring form.
Glycogen …
occurs in animal cells and has branches.
Which fact is most important in explaining why cellulose is a better structural material than starch?
A. Links between alpha glucoses
are stronger than links between beta glucoses.
B.Branched polymers can form more hydrogen bonds than unbranched polymers.
C. Alpha-linkages make it easier for the polymer to coil into a helix.
D. C-C links are stronger than C-O-C links.
E. Polymers made of fructose are stronger than polymers made of glucose.
C. Alpha-linkages make it easier for the polymer to coil into a helix.