Unit 1 - Chemistry of Life

Which feature of model 1 best illustrates how biological information is coded in a DNA

molecule?

• The 5' and 3' labels at the ends of each strand.

• The labeling of the hydrogen bonds between base pairs.

• The lines connecting sugars and phosphate groups that represent covalent bonds.

• The linear sequence of the base pairs.

Tags

NGSS.HS-LS3-1

Figure 1 represents a segment of DNA. Radiation can damage the nucleotides in a DNA molecule. To repair some types of damage, a single nucleotide can be removed from a DNA molecule and replaced with an undamaged nucleotide.

Which of the four labeled bonds in Figure 1 could be broken to remove and replace the cytosine nucleotide without affecting the biological information coded in the DNA molecule?

(Last Option Isn't An Answer, Just A Picture Part Of This Q)

• Bond X only.

• Bond W only.

• Bonds Y and Z at the same time.

• Bonds W and Z at the same time.

• 

Tags

NGSS.HS-LS3-2

A student wants to modify model 1 so that it represents an RNA double helix instead of a DNA double helix. Of the following possible changes, which would be most effective in making model 1 look more like RNA than DNA?

• Changing the sequence of the base pairs.

• Changing the deoxyriboses to riboses by adding −OH groups.

• Changing the shapes of the nitrogenous bases to match those shown in model 2.

• Changing the sugar-phosphate backbone to a ribbon, as shown in model 3.

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.

Based on Figure 1, which of the following best compares the atomic structures of starch and cellulose?

• Starch is composed of carbon, hydrogen, and oxygen, while cellulose also contains nitrogen.

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

• Starch is composed of monomers that each have a CH2OH group, while cellulose only has a CH2OH group on every other monomer.

• Starch and cellulose are composed of identical monomers and therefore have identical structures.

• (THIS ISNT ANSWER JUST INFO)

  
  

  Test Tube Polysaccharide Added Enzyme Added Glucose Detected after 5 Minutes at 37°C

  1 Cellulose A No

  2 Cellulose B Yes

  3 Starch A Yes

  4 Starch B No

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.

Based on the information provided, which of the following statements best describes why starch and cellulose provide different functions in plants?

• The differences in the assembly and organization of the monomers of these two polymers result in different chemical properties.

• Since starch and cellulose are composed of identical monomers, the cellular environment where they are located controls their function.

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

• The monomers of starch are connected by ionic bonds, making it ideal for energy storage for plants.

• (Not Answer Just Table)

  
  

  1 Cellulose A No

  2 Cellulose B Yes

  3 Starch A Yes

  4 Starch B No

Tags

NGSS.HS-LS2-3

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.

Which of the following best describes the process that adds a monosaccharide to an existing polysaccharide?

• The monosaccharide is completely broken down by a specific enzyme and then the atoms are reorganized and made into a polysaccharide.

• Ionic bonds are formed between adjacent carbon atoms of the monosaccharide and the polysaccharide by adding water (H2O) and a specific enzyme.

• A specific enzyme removes the hydrogen ( H ) from the monosaccharide and the hydroxide ( OH ) from the polysaccharide, creating a bond between the two and creating a water ( H2O ) molecule.

• A specific enzyme removes two hydroxides (OH), one from the monosaccharide, and one from the polysaccharide, creating a bond between the two monosaccharides and creating a hydrogen peroxide ( H2O2 ) molecule.

• (NOT ANSWER, JUST TABLE)

  
  

  1 Cellulose A No

  2 Cellulose B Yes

  3 Starch A Yes

  4 Starch B No

Tags

NGSS.HS-LS1-6

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.

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 synthesize cellulose.

• Cattle would have to convert cellulose to starch before digesting it.

• Cattle would have to start producing enzyme B without the help of the bacteria.

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

• (NOT ANSWER, JUST TABLE)

  
  

  Test Tube Polysaccharide Added Enzyme Added Glucose Detected after 5 Minutes at 37°C

  1 Cellulose A No

  2 Cellulose B Yes

  3 Starch A Yes

  4 Starch B No

As shown in the diagram, when 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 closer together than those in liquid water, so the ice prevents the passage of air to the water, maintaining a constant gas mixture in the water.

• The water molecules in ice are closer together than those in liquid water, so the ice forms a barrier that protects the organisms in the water from the freezing air temperatures.

• 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.

• The water molecules in ice are farther apart than those in liquid water, so the ice floats, preventing the escape of gases from the liquid water.

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-4