Name: _______________________________________________________ Date: _________________ Period: ________
Organic Molecules Packet Organic molecules are the molecules which exist in all living things. They are life’s building blocks. All living things are formed from these organic molecules. There are four categories of organic molecules: carbohydrates, lipids, proteins, and nucleic acids. 1) How are organic molecules related to all living things? ________________________________________________________________________ 2) Name the 4 categories of organic molecules. ________________________________________________________________________ Organic molecules have four common characteristics. First, they are all carbon based, meaning they all contain carbon. They are formed from just a few elements which join together to form small molecules which join together, or bond, to form large molecules. Another characteristic of all organic molecules is that each is built from a single type of building block, or monomer. For example, the monomer of carbohydrates are simple sugars called monosaccharides. The monomer of lipids are called fatty acids. The monomer of proteins are called amino acids. The monomer of nucleic acids are called nucleotides. When these building block monomers are joined together, they form a larger molecule called a polymer. For example, a protein is a polymer that is formed from many amino acids. 3) All organic molecules are based on which element? ______________________________ 4) Many times, organic molecules join to form long chains. What are the long chains called? 5) How are the building blocks of organic molecules like bricks? ________________________________________________________________________ 6) What is the building block of each of the four classes of organic molecule? a. The building block of carbohydrates are _________________________________. b. The building block of proteins are ___________________________________. c. The building block of lipids are ______________________________________. d. The building block of nucleic acids are ________________________________.
7) What is a polymer in relation to a monomer? ________________________________________________________________________ Another 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. 8) What determines how organic molecules will look and behave? ________________________________________________________________________ 9) What are three common characteristics of all organic molecules? a. ___________________________________________________________________ b. ___________________________________________________________________ c. ___________________________________________________________________ Carbohydrates Carbohydrates are the most common organic molecule because they make up most plant matter. They are made from carbon, hydrogen, and oxygen. Their building block (monomer) is called a simply sugar or monosaccharide. Monosaccharides consist of carbon rings. When two monosaccharides combine, they form a disaccharide (di = two). When more than two monosaccharides join together, a polysaccharide (poly = many) is formed. 10)
What are the elements contained in a carbohydrate? _______________________
11)
What is the monomer of a carbohydrate? ________________________________
12)
What is a monosaccharide?
________________________________________________________________________ 13)
What is the shape of a monosaccharide? _________________________________
14)
What is a disaccharide?
________________________________________________________________________ 15)
How does a polysaccharide differ from a disaccharide?
________________________________________________________________________ There are three classes of carbohydrate polysaccharides. The first is starch. Starch is a carbohydrate used in food storage in plants. Potatoes, pasta, and rice and rich in starch. Starches are very valuable because they provide a quick form of energy for the body. The second is glycogen. Glycogen is used for food storage in animals. The third is cellulose. Cellulose is used for structural support in plant cells. Sugars can be detected in foods through a simple lab test. To find out if a food contains starch, iodine is placed on the food. A food containing starch will turn black when in contact with iodine. A test for simple sugars involved mixing the food with a blue liquid called Benedict’s solution and then heating the mixture. If the food is positive for simple sugars, the heating process will cause the Benedict’s solution to turn red, orange, or green. 16)
Name the three classes of carbohydrates.
________________________________________________________________________ 17)
Which carbohydrate is used by animals as food storage? ____________________
18)
Which carbohydrate is used to support plant cells? _________________________
19)
Which carbohydrate is used by plants as food storage? ______________________
20)
Why would an athlete eat a big pasta dinner the night before a race?
________________________________________________________________________ 21)
Which chemical is used to detect starch in foods? __________________________
Lipids Lipids are a class of organic molecule which includes fats and oils, and has the function of long-term storage of energy in the body. The building block monomer of lipids are called fatty acids, which is a chain of carbons with hydrogen attached to each side. Saturated fats unhealthy fats usually from animal sources. They are also solid at room temperature. They
are called “saturated” because they are filled with H atoms. Unsaturated fats missing or lacking hydrogen atoms. Unsaturated fats are from plant sources, are healthy, and liquid at room temperature. 22)
What are the monomers of lipids? ______________________________________
23)
Name two common examples of lipids. __________________________________
24)
How is the structure of a saturated fat different from an unsaturated fat?
________________________________________________________________________ 25)
Which fats are typically: a. From animals? ________________________________ b. Liquid at room temperature? __________________________________ c. Healthy? _______________________________
Proteins Proteins are organic molecules that form muscles, transport O2, and act as hormones and enzymes. Most importantly, proteins determine how our bodies look and function. The monomers of proteins are called amino acids. Proteins are made from long chains of amino acids held together by a peptide bond. That is why a long chain of amino acids may also be known as a polypeptide. 26)
Name a function of protein.
________________________________________________________________________ 27)
What are the monomers of proteins? ____________________________________
28)
What is the name of the bond that holds amino acids together? ______________
There are 20 different kinds of amino acids. These amino acids consist of five separate parts: (1) a central Carbon atom, (2) a carboxyl group of atoms (COOH), (3) an amino group of atoms (NH2), (4) a hydrogen atom, (5) an “R” group of atoms. The only difference between all 20 amino acids is the R group. Some R
groups are very small, while others are very large. The sequence and shape of the R groups controls the shape and function of the protein. 29)
How many different types of amino acids exist? ___________________________
30)
Which part of an amino acid varies from one amino acid to another? __________
31)
What determines the shape and function of a protein? ______________________
Nucleic Acids The fourth class of organic molecules are the nucleic acids. This class involved the genetic materials DNA and RNA. DNA is often called the “blueprint of life” because it contains instructions on how to make proteins in the body. Each individual’s DNA is unique, which means that each individual has a unique set of proteins; that is why each of us looks and behaves differently from others. RNA creates 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 instructions from DNA to the cytoplasm where the protein is created. The monomer of nucleic acids are called nucleotides. All nucleic acids are formed from a series of these nucleotides. Nucleotides consist of three parts: (1) a five carbon sugar, (2) a phosphate group, and (3) a nitrogen base. 32)
What are the two types of nucleic acid? __________________________________
33)
What is the role of DNA? ______________________________________________
34)
What is the role of RNA? ______________________________________________
35)
What are the building blocks (monomers) of nucleic acids?
________________________________________________________________________ 36)
What are the three subunits of a nucleotide?
________________________________________________________________________ The structure of DNA resembles that of a twisted ladder, called a “double helix.” The rails (outside) of the DNA ladder are made from alternating sugars, called deoxyribose, and
phosphates (sugar-phosphate-sugar-phosphate-sugar-phosphate). The rungs (inside) of the ladder are made of four different kinds of nitrogen containing bases. The four nitrogen containing bases are called: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). The nitrogen bases attach to each other in a very specific way: Adenine always attaches to Thymine, and Cytosine always attaches to Guanine. 37)
What is the special shape of a DNA molecule called? ________________________
38)
What are the outside rails of a DNA molecule made from?
________________________________________________________________________ 39)
What are the four nitrogen containing bases of DNA called?
________________________________________________________________________ 40)
What does cytosine always bond with? __________________________________
41)
What does thymine always bond with? __________________________________
RNA is very similar to DNA, except for a few differences. First, where the sugar in DNA is called deoxyribose, RNA is made from a different sugar called ribose. Second, where DNA is a double helix, RNA has just one strand. Third, where the nitrogen bases in DNA are A, T, C, G, in RNA the nitrogen bases are A, U, C, G. The U = uracil in RNA, and takes the place of the T in DNA. Fourth, DNA cannot leave the nucleus of the cell, while RNA can. 42)
List four differences between DNA and RNA. a. ___________________________________________________________________ b. ___________________________________________________________________ c. ___________________________________________________________________ d. ___________________________________________________________________
43)
List three similarities between DNA and RNA. a. ___________________________________________________________________ b. ___________________________________________________________________ c. ___________________________________________________________________
