Biology Assessment 2

What are the three parts of this monomer?

Nucleotides consist of three parts: a five-carbon sugar, a phosphate group and a nitrogen base.

How are organic molecules related to all living things?

Organic molecules are the molecules which exist in all living things. They are life's building blocks. All things are formed from these organic molecules.

All of the organic molecules are based on which element?

Organic molecules have four common characteristics. First, they are all carbon based, meaning they all contain carbon.

What are the three classes of carbohydrates?

The first is starch. The second is glycogen. The third is cellulose.

What are the rails of the ladder made of?

The rails of the DNA ladder are made from alternating sugars and phosphates (sugar-phosphate-sugar-phosphate-sugar...).

How are the rails of the ladder kept together?

The rails of the ladder are held together because the bases from one rail bond to the bases from the other rail to form rungs.

What are the four different DNA bases?

The rungs of the ladder are made of four different kinds of bases, with one base hanging off of the sugar portion of each rails. The four bases are A, T, C and G.

'A' always pairs with what base?

T

What is a polymer?

A polymer is a more complex molecule created by forming monomers together.

What is the building block of proteins?

Amino Acids

What part of the amino acid varies from one amino acid to another?

Amino acids consist of five separate parts. The first is a central carbon atom. Second is a carboxyl group (-COOH). Third is an amino group (-NH2). Fourth is a hydrogen. The fifth group is a variable 'R' group. The only difference in the 20 kinds of amino acids is the "R" group.

How many different amino acids are there?

Around 20

What are the six most common elements of life?

CHNOPS - Carbon, Hydrogen, Oxygen, Phosphorous, Sulfur

What is cellulose used for?

Cellulose is used for structural support in plants (stems, leaves).

What are the two types of nucleic acids?

DNA and RNA

What is the role of DNA?

DNA is the blueprint of life because it contains instructions on how to make proteins in the body.

List four differences between DNA and RNA.

First, where the sugar in DNA is deoxyribose, the sugar in RNA is ribose. Second, where DNA is a double helix, RNA has just one strand. Third, where the bases in DNA are C,G, A and T, in RNA the bases are C, G, A and U. The U in RNA takes the place of the T in DNA. Fourth, DNA cannot leave the nucleus of the cell and RNA can.

What is the building block of each of the four classes of organic molecules?

For example, the building block of carbohydrates is sugar, the building block of lipids is fatty acids, the building block of protein is amino acids and the building block of nucleic acids is the nucleotide.

Which involves food storage in animals?

Glycogen is used for food storage in animals.

What is the building block of lipids?

Lipids are a class of organic molecules which includes fats and oils, and has the function of long-term storage of energy in the body.

Explain the solubility of lipids.

Lipids are soluble (dissolve) in oil but are insoluble (don't dissolve) in water. When mixed with water, the lipid will float on top to form a separate layer.

Why would an athlete have a big pasta dinner the night before a race?

Potatoes, pasta and rice are rich in starch. Starches are very valuable because they provide a quick form of energy for the body.

What is the name of the bond that joins amino acids?

Proteins are made of amino acids combined through a dehydration link called a peptide bond.

What are some of the functions of proteins?

Proteins are organic molecules that form muscles, transport O2 (hemoglobin), and act as hormones and enzymes. Most importantly, proteins determine how our bodies look and function.

How does the role of RNA differ from that of DNA?

RNA is a copy of DNA. Because DNA can't leave the cell's nucleus, and because proteins are constructed outside of the nucleus in the cytoplasm, the RNA is necessary to carry the instructions from DNA to the cytoplasm where the protein is made.

Name examples of lipids

Saturated fat, unsaturated fat

What is a saturated fatty acid?

Saturated fats have two carbons attached to each carbon (except the one at the end).

Which involves food storage in plants?

Starch is a carbohydrate used in food storage in plants.

What does a monosaccharide look like?

Sugars (monosaccharides) consist of carbon rings.

What is a monosaccharide?

The building block of carbohydrates that consists of carbon rings.

Describe the structure of a fatty acid.

The building block of lipids is the fatty acid, which is a chain of carbons with hydrogen attached to each side.

What determines how organic molecules will look and behave?

The last common characteristic of all organic molecules is that their form determines their function. That means that their shape determines how they will behave and how they will react with other molecules.

What is the building block of nucleic acids?

The monomer of nucleic acids is the nucleotide.

What determines the shape and function of a protein?

The sequence and shapes of the "R" groups control the shape and function of the protein.

Describe the structure and shape of DNA.

The structure of DNA resembles that of a twisted ladder. This twisted ladder of DNA is called a 'double helix.'

How are the building blocks of organic molecules like bricks?

The third characteristic of all organic molecules is that each is kind of organic molecule is built from a single type of building block. When these building blocks are joined together, they form a large molecule (polymer), just as bricks joined together form a wall.

What is the building block of carbohydrates?

Their building block a single sugar called a monosaccharide.

Name four categories of organic molecules which form the basis of all living things.

There are four categories of organic molecules: Carbohydrates, lipids, proteins and nucleic acids.

What are the four common characteristics of all organic molecules?

They are all carbon based. They are formed from just a few elements which join together to form small molecules which join together, or bond, to form large molecules. The third characteristic of all organic molecules is that each is kind of organic molecule is built from a single type of building block. The last common characteristic of all organic molecules is that their form determines their function. That means that their shape determines how they will behave and how they will react with other molecules. For example, the order of amino acids in a protein will determine the shape and function of the protein just as the order of words in a sentence shapes the meaning of the sentence.

List three similarities between DNA and RNA.

They are both formed from nucleotides. They both have backbones of sugar phosphate. They both serve to transfer genetic code.

Many times, the molecules join to form long chains with what kind of backbone?

They are formed from just a few elements which join together to form small molecules which join together, or bond, to form large molecules.

What are the elements contained in carbohydrates?

They are made from carbon, hydrogen and oxygen.

How would you test for lipids, and what is a positive result?

To test for the presence of lipids in food, the sample is placed on a piece of brown or newspaper, and then the paper is held up to the light. A test that is positive for lipids will have a oily spot that is translucent, or clear, on the paper.

How does a polysaccharide differ from a disaccharide?

When more than two monosaccharides join together, a polysaccharide (poly = many) is formed.

What is a disaccharide?

When two monosaccharides, or sugars, combine, they form a disaccharide (di = two).

What part of the ladder do these bases form?

the bases from one rail bond to the bases from the other rail to form rungs. The bases from one side of the ladder attach to the bases hanging from the other rail.