Biology- Chapter 2 & 3 Quiz

What may a nucleotide of DNA contain?

Deoxyribose. thymine, and a phosphate group

How do the differences in amino acid sequences lead to different protein functions?

Different amino acids produce different proteins because of the secondary bonds

What bodily process would most likely be hindered by a lack of water in the body?

Digestion

What role do electrons play in dehydration synthesis and hydrolysis?

Electrons are added to OH and H ions in dehydration synthesis. They are removed from OH and H in hydrolysis.

What hormones are made from cholesterol?

Estradiol and testosterone

What are three examples of how the characteristics of water are important in maintaining life?

First, the lower density of water as a solid versus a liquid allows ice to float, forming an insulating surface layer for aquatic life. Second, the high specific heat capacity of water insulates aquatic life or bodily fluids from temperature changes. Third, the high heat of vaporization of water allows animals to cool themselves by sweating.

What is an example of a monosaccharide?

Fructose

Cellulose and starch are examples of —

polysaccharides

The image of "beads on a string" is often used to describe the sequence of amino acids in a polypeptide. Which aspect of protein structure does this image most resemble?

primary structure

Which statement best describes the production of sucrose, maltose, and lactose?

Glucose and fructose combine to form sucrose. Glucose and galactose combine to form lactose. Two glucose monomers combine to form maltose.

For a covalent bond to be polar, the two atoms that form the bond must have

different electronegativities

Which of the following pairs of functional groups characterizes the structure of an amino acid?

A

What type of bond joins the molecules in the disaccharide lactose, and what molecule is joined with glucose to form lactose?

A glycosidic bond between glucose and galactose

Which type of body cell would have a higher amount of cholesterol in its membrane?

A red blood cell

What is cholesterol specifically classified as?

A steroid

The chemical structure for the nitrogenous base adenine is shown above. It is an important biomolecule and is find in which three of the following?

ATP, DNA, and RNA

What are the monomers that make up proteins called?

Amino Acids

What type of protein facilitates or accelerates chemical reactions?

An enzyme

Which statement describes how water is pulled up through the xylem to the leaves of the plant?

As water exists the leaf, signals are sent to the roots to pump more water up to the leaves through the xylem by adhesion

Where is cholesterol found in cell membranes?

Attached to the inner side of the membrane

Proteins are polymers composed of structural monomers called amino acids. Which of the following pairs of functional groups characterizes the structure of an amino acid?

B

A wide range of marine mammals and fish live in the severe conditions of the Artic ocean. Whales, dolphins, walruses, and seals all make their home in this North Polar region which is covered by ice most of the year. Which of the following is used for insulation and buoyancy in marine Artic animals?

Lipids

Cholesterol is soluble in ether, an organic solvent, but it is not soluble in water. Based on this information, to which class of biological molecules does cholesterol belong?

Lipids

What are three functions that lipids serve in plants and/or animals?

Lipids serve in the storage of stored energy molecules, as signaling molecules, and as structural components of hormones.

What functional group is NOT polar

Methyl

What are enantiomers?

Molecules that share the same chemical bonds but are mirror images of each other

The "building blocks" of polysaccharides are _______, and the blocks are covalently linked together by ______.

Monosaccharides; gylcosidic linkages

The genetic code is the set of rules by which information decided within genetic material is translated into proteins by living cells. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries. Which of the following is used to carry the genetic code?

Nucleic Acids information

What are classified as lipids?

Oils and waxes

What is removed during the formation of nucleic acid polymers?

Phosphates

How do phospholipids contribute to cell membrane structure?

Phospholipids orient their heads toward the polar molecules and tails in the interior of the membrane, forming a bilayer.

Dehydration synthesis leads to the formation of what?

Polymers and water

The word hydrolysis is defined as the lysis of water. how does this apply to polymers?

Polymers break apart be separating water into hydrogen and a hydroxyl group that are added to the monomers

Beside its use in hormone production, for what does the body use cholesterol?

Production of bile salts

What is found in RNA that is NOT in DNA?

Ribose and uracil

Compare and contrast saturated and unsaturated triglycerides.

Saturated triglycerides contain single bonds and are solid at room temperature, while unsaturated triglycerides contain double bonds and are liquid at room temperature.

The α-helix and the β-pleated sheet are part of which protein structure?

Secondary structure

What is NOT a functional group that can bond with carbon?

Sodium

Polar ice caps are dome-shaped sheets of ice found near the North and South Poles. They form because high latitude polar regions receive less heat from the sun than any other areas on Earth. As a average, average temperatures at the poles can be very cold. The polar ice caps contain the majority of Earth's supply of freshwater. In fact, scientists estimate that 70 percent of Earth's freshwater supply in an ice sheet at the South Pole. Why does ice stay at the top of oceans instead of sinking to the bottom.

Solid ice is less dense than liquid water

Mammals do not produce digestive enzyme B. However, sheep and cattle are two types of mammals that contain microorganisms in their digestive tract that produce enzyme B. Based on Figure 1, which of the following best compares the atomic structures of starch and cellulose?

Starch and cellulose are composed of repeating glucose monomers; however. in cellulose every other glucose monomer is rotated 180 degrees.

Which statement describes some of the differences between cellulose and starch?

Starch is branched and cellulose is unbranched. Both molecules are found in plants.

What is a function of proteins in cells?

Structure

How might this change affect the structure and function of the protein?

The R=group of the new amino avid, valine, as different chemical properties than the R-group for cyteine. This will cause the protein to misfold and not function properly in the cell

Which characteristic is NOT true for saturated fats?

They tend to dissolve in water easily.

Which fat serves as an animal's major form of energy storage?

Triglycerides

Which fat has the least number of hydrogen atoms?

Unsaturated fat

Which of the following is correct regarding the properties of water?

Water absorbs energy when it changes from a liquid to a gas.

What are the four types and functions of RNA?

mRNA is a single-stranded transcript of DNA. rRNA is found in ribosomes. tRNA transfers specific amino acids to a growing protein strand. miRNA regulates the expression of mRNA strands.

Aldehydes and ketones are very similar in that they both contain

a C -O group

The structure above could be any of the following except a

molecule that is the energy source for most anabolic activity in cells

What is a protein's chaperone

A chemical that helps the protein fold properly

What is DNA's structure described as?

A double helix

Where is the linkage that combines two amino acids?

Between the carboxyl group of one amino acid and the amino group of the other

Which of the following best describes a structural similarity between the two molecules shown in Figure 1 that is relevant to their function>

Both molecules contain nucleotides that form base pairs with other nucleotides which allows each molecule to act as a template in the synthesis of other nucleic acid molecules.

Which statement describes how buffers help prevent drastic swings in pH?

Buffers absorb excess hydrogen and hydroxide ions to prevent increases or decreases in pH. An example is the bicarbonate system in the human body.

Biopolymers are polymers produced by living organisms. Since they are polymers, biopolymers contain monomeric units that are covalently bonded to form larger structures. Which of the following biopolymers includes glycogen, chitin, cellulose and glucose?

Carbohydrates

What property of carboxyl makes carboxyl-containing molecules hydrophilic? Which macromolecules contain carboxyl?

Carboxyl groups release H+, making its parent molecule hydrophilic. It is found in amino acids and fatty acids.

Which of the following would most likely occur if cattle lost the ability to maintain a colony of microorganisms in their digestive tract?

Cattle would no longer be able to use cellulose as a primary source of glucose.

Plant cells contain what in abundance?

Cellulose

What may cause a protein to denature?

Change in pH (all above should be correct though tbh)

A student wants to modify a model of DNA so that it represents a double helix of RNA instead of a DNA double helix. Of the following possible changes, which would be the most effective in making DNA look more like RNA?

Changing the deoxyriboses by adding -OH groups

A student wants to change a model of a strand of DNA into a model of RNA. Of the following possible changes, which would be most effective?

Changing the deoxyriboses to riboses by adding -OH groups

A culture of Spriogyra (an phototropic alga) in maintained in a water solution containing dissolved carbon dioxide and a source of phosphates but lacking nitrogen compounds.A researcher determines the rates of synthesis of several organic compounds, found in the Spriogyra before and after several weeks in the water solution. Which of the following graphs best illustrates a likely result of the experiment?

Graph with carbohydrates equal, protien at 6 and 4, lipids equal, and nucleic acids at 4 and 2.

Why is it impossible for humans to digest food that contains cellulose?

Human digestive enzymes cannot break down the ββ-1,4 glycosidic linkage in cellulose, which requires a special enzyme absent in humans.

Which type of bond exemplifies a weak chemical bond.

Hydrogen bond

Why are hydrogen bonds and van der Waals interactions necessary for cells?

Hydrogen bonds and van der Waals interactions form weak associations between molecules, providing the necessary shape and structure for DNA and proteins to function in the body

During the breakdown of polymers, which reaction takes place?

Hydrolysis

Energy is released as a result of which chemical reaction?

Hydrolysis

In the metabolism of the cell, why is hydrolysis used?

Hydrolysis is used to break down polymers.

Where is the largest amount of DNA found in a eukaryotic cell?

In the nucleus

Why can some insects walk on water?

Insects can walk on water because of its high surface tension.

What statement is false?

Ionic bonds are generally stronger than covalent bonds.

What forms ionic bonds?

Ions with opposite charge

What are atoms that vary in the number of neutrons found in their nuclei called?

Isotopes

Figure 1 shows a short segment of a double-stranded nucleic acid molecule. Figure 1. A short segment of a double stranded nucleic acids molecule. Which one of the following statements is correct about the molecule shown in Figure 1?

It is DNA because of the nature of the hydrogen bonds between guanine and cytosine

Biomolecules have intramolecular forces that hold them together as a unit. Biomolecules also exhibit intermolecular forces when interacting with other biomolecules. Which of the following is an example of a hydrogen bond?

The attraction between a hydrogen of one water molecule and the oxygen of another water molecule

Which of the following is an example of a hydrogen bond?

The attraction between a hydrogen of one water molecule and the oxygen of another water molecule

What is the maximum number of atoms or molecules a single carbon molecule can bond with?

The carbon atom has four electrons in its valence shell. Therefore, bonding four more electrons will complete its octet, allowing it to attain a stable configuration. A carbon molecule can therefore bond with a maximum of four other atoms.

Based on the figure, which statement best describes the observed relationship between atmospheric CO2 enrichment and plant growth under ideal and stressed conditions?

The increase in atmospheric CO2 resulted in a greater increase in plant growth under stressed conditions than under ideal conditions

Different polysaccharides are used by plants for energy storage and structural support. The molecular structures for two common polysaccharides are shown in Figure 1. Starch is used by plants for energy storage, and cellulose provides structural support for cell walls. The monomer used to construct both molecules is glucose. A study determined the effect of two different digestive enzymes, A and B, on these two polysaccharides. Table 1 presents the data from the study. Mammals do not produce digestive enzyme B. However, sheep and cattle are two types of mammals that contain microorganisms in their digestive tract that produce enzyme B.Based the information provided, which of the following statements best describes why starch and cellulose provide different functions in plants?

The monomers of cellulose are connected by covalent bonds, making it idea for structural support.

Which of the following correctly illustrates a dipeptide and an amino acid in the optimal position to forma tripeptide?

The one with a C double bonded to O and a single bond with OH and has only H on the far left

What is the pH scale and how does it relate to living systems? Give an example of how drastic pH changes are prevented in living systems.

The pH scale ranges from 0 to 14, where anything below 7 is acidic and above 7 is alkaline. The bicarbonate system in the human body buffers the blood.

What is the pH scale, and how does it relate to living systems? Give an example of how drastic pH changes are prevented in living systems.

The pH scale ranges from 0 to 14, where anything below 7 is acidic and above 7 is alkaline. The bicarbonate system in the human body buffers the blood.

Which of the following is the most likely reason for the difference in leaf growth?

The phosphorus=starved plant was unable tos= synthesize both the required nucleic acids and lipids, limiting growth.

Of what are phospholipids important components?

The plasma membrane of animal cells

As shown in the diagram, which environmental temperatures drop below freezing, a layer of ice typically forms on the surface of bodies of freshwater such as lakes and rivers. Which of the following best describes how the structure of ice benefits the organisms that live in the water below?

The water molecules in ice are farther apart than those in liquid water, so the ice floats, maintaining the warmer, denser water at the lake bottom.