Bio 111
What is the major structural difference between starch and glycogen?
the amount of branching that occurs in the molecule
One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus, H2CO3 <-->HCo3- + H+ If the pH of the blood drops, one would expect a) the HCO3- to act as an acid and remove excess H+ with the formation of H2CO3. b)the concentration of bicarbonate ion (HCO3-) to increase. c)the concentration of hydroxide ion (OH-) to increase. d)a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-. e)theHCO3- to act as a base and remove excess with the formation ofH2CO3 .
theHCO3- to act as a base and remove excess with the formation ofH2CO3 .
People who are lactose intolerant cannot extract energy from milk because
they are missing an enzyme
In an ethane (C2H6) molecule, each carbon atom is bonded to ________ hydrogen atoms.
three
How many electron pairs are shared between carbon atoms in a molecule that has the formula C2H4?
two
Which of the following is a major difference between RNA AND DNA
type of sugar
36) Which of the following are qualities of any good scientific hypothesis? I. It is testable. II. It is falsifiable. III. It produces quantitative data. IV. It produces results that can be replicated. A) I only B) II only C) III only D) I and II E) III and IV
Answer: D
Which of the following is the best description of an atom's physical structure
Atoms are little bubbles of space with mass concentrated at the center of the bubble.
If one strand of a DNA molecule has the sequence of bases 5' ATTGCA 3', the other complementary strand would have the sequence (pay attention to the direction of the strands): A)5'UAACGU3'. B)5'TGCAAT3'. C)3'UAACGU5' D)5'TAACGT3'
B
28) What component of amino acid structure varies among different amino acids? A) the long carbon-hydrogen tails of the molecule B) the presence of a central C atom C) the components of the R-group D) the glycerol molecule that forms the backbone of the amino acid
C) the components of the R-group
What are the monomers of carbohydrates/proteins/nucleic acids?
Carbohydrates -monosaccharides Lipids -glycerol and fatty acids Nucleic acids-nucleotides Proteins- amino acids
Which of the four main classes of large biological molecules does not consist of polymers
Carbohydrates, lipids, proteins, nuclei acids
What are the main functions of carbohydrates/lipids/nucleic acids
Carbohydrates-source of energy Lipids- fats Nucleic acids-coding your traits DNA AND RNA
What element is protein made up of
Carbon, hydrogen , oxygen, nitrogen
What element is nucleic acids made up of?
Carbon, hydrogen,oxygen ,nitrogen,phosphorus
Which element is carbohydrates made up of
Carbon, oxygen , and hydrogen
On food packages, to what does the term insoluble fiber refer?
Cellulose
How do beano works
Contains a natural food enzyme that helps prevent gas before it starts it works with your body digestion to break down in carbohydrates
How does lactid work
Contains lactase a natural enzyme that helps break down lactose into two simple sugars galactose and glucose
Which molecule shown above contains a functional group that is a part of the molecule known as the "energy currency of living organisms
D
43) If an atom has a charge of +1, which of the following must be true? A) It has two more protons than neutrons. B) It has the same number of protons as electrons. C) It has one more electron than it does protons. D) It has one more proton than it does electrons.
D) It has one more proton than it does electrons.
10) A molecule with the chemical formula C6H12O6 is probably a _____. A) fatty acid B) polysaccharide C) nucleic acid D) monosaccharide
D) monosaccharide
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.
Why does ice float in liquid water?
Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water.
Give an example of a storage polysaccharides
Starch and glycogen and structural polysaccharides such as cellulose. And chitin
What is glycogen
Stored glucose
A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to
Surface of hydrocarbons
Humans can digest starch but not cellulose because.
humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose.
The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called?
hydrogen bond
Macromolecules
large molecule
What are polymers?
long chains of repeating units
When the atoms involved in a covalent bond have the same electronegativity, what type of bond results?
nonpolar covalent bond
The relation between amino acid and polypeptide is similar to the relation between
nucleotide, nucleic acid
Compared with 31P, the radioactive isotope 32P has
one more neutron
A covalent bond is likely to be polar when
one of the atoms sharing electrons is more electronegative than the other atom
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
polar covalent bonds
about 25 of 92 natural elements are known to be essential to life which were these 25 elements make up approximately 96% of living matter A)carbon ,hydrogen,nitrogen,oxygen B)carbon, sodium,hydrogen, nitrogen C)carbon, oxygen,phosphorus, hydrogen D)oxygen, hydrogen,calcium, nitrogen
A
What type of enzyme breaks 1-4 linkages between glucose monomers
1 4 glycosidic linkages
How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule?
19
Homo sapiens have 23 pairs of chromosomes. this implies that ________.
46 double-stranded DNA molecules are present in each somatic cell
53) Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely A) positively charged. B) negatively charged. C) without charge. D) hydrophobic. E) nonpolar.
A
What is the relationship between monomers and polymers?
A monomer is a single unit while a polymer is a monomer but linked together
Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following statements is correct about the atoms in ammonia (NH3)? A) Each hydrogen atom has a partial positive charge. B) The nitrogen atom has a strong positive charge. C) Each hydrogen atom has a slight negative charge. D) The nitrogen atom has a partial positive charge. E) There are covalent bonds between the hydrogen atoms.
Each hydrogen atom has a partial positive charge
Polysaccharides
General molecule
The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound.
H2S
A carbon atom has 6 electrons however, its valency is 4. This is because the carbon atom
Has only 2 electrons in its first shell and 4 in the second shell
What is high fructose corn syrup?
It is a sweeter that is made changing the sugar (glucose) In cornstarch into fructose
Agrobacterium infects plants and causes them to form tumors. You are asked to determine how long a plant must be exposed to these bacteria to become infected. Which of the following experiments will provide the best data to address that question?
Measure the number of tumors formed on plants, which are exposed to Agrobacterium for different lengths of time.
Dissacharides
Molecular structure
How does a monosaccharides look like
Molecular structure
What bond links carbohydrates monomers
Monosaccharide
Differentiate between monosaccharides, disaccharides and polysaccharides.
Monosaccharides generally have molecular formulas that are some multiple of CH2O; thet are monomers ("building blocks" ) of carbohydrates. Glucose is the most common monosaccharide, and glucose along w other monosaccharides are major nutrients for cells. Disaccharides is made up of two monosaccharides joined by a glycosidic linkage (covalent bond bw two monosaccharides by a dehydration reaction). Polysaccharides are macromolecules (few hundred to a few thousand monomers) of carbohydrates. They serve as storage material, and can be hydrolyzed to provide sugar for cells. Polysaccharides can also serve as building material for structures that protect the cell or the entire organism (function determined by sugar monomers and position of glycosidic linkages).
Why can't humans digest cellulose
The glycoside bond in polymers that have α glucose can easily be broken down by humans but glycoside bonds in β glucose polymers can not because the bonds joining the glucose subunits in cellulose are different than those in starch, causing both polymers to have a different shape; starch is made of α glucose subunits joined by 1-4 linkages, thus have a helical shape, while cellulose contain β glucose subunits joined by 1-4 linkages and has a straight shape. Humans do not have the enzymes that digest by hydrolyzing the β linkages because of the distinct difference in shapes.
Grains contain fiber and starch -which part of the grain contains fiber and which part of the grains contains starch
The largest part of a kernel of grain which contains starch and the outer protective covering of a kernel of a grain which is a good source of fiber
what makes lipids/fats hydrophobic ?
The presence of relativity non polar C - H bonds
Which of the following statements concerning unsaturated fats is true?
They have double bonds in the carbon chains of their fatty acids.
When nucleotides polymerize to form a nucleic acid _____.
a covalent bond forms between the sugar of one nucleotide and the phosphate of a second
What are monomers?
a molecule that can be bonded to other identical molecules to form a polymer.
Which of the following descriptions best fits the class of molecules known as nucleotides? A) a pentose sugar and a purine or pyrimidine B) a nitrogenous base and a pentose sugar C) a phosphate group and an adenine or uracil D) a nitrogenous base and a phosphate group E) a nitrogenous base, a phosphate group, and a pentose sugar
a nitrogenous base, a phosphate group, and a pentose sugar
If you change the number of neutrons in an atom, you create _____.
an isotope
Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a hydrocarbon chain with the same number of carbon atoms, but with one or more double bonds, will
be more constrained in structure
Which of the following categories includes all others in the list?
carbohydrate
What are the four main classes of large biological molecules
carbohydrates, lipids, proteins, nucleic acids
2) Which of the following is NOT a polymer?
glucose
