9th Grade. Organic molecules lesson. Proteins

Hey there. The newest lesson on Proteins. Enjoy!
Proteins

Learning Outcomes

Content: to be able to explain different structures and functions of proteins.

Language: to be able to use specific vocabulary in explaining proteins in your body.

Vocabulary 

enzymes 

carrier 

side chain 

polypeptide 

to denaturate 

1 (pair work). Which of these things are proteins? Can you think of other examples?

1 egg-white       2 hemoglobin      3 green leaf

2 (individual work). True or False. Correct the false sentences. Use the text below.
1___Proteins are made of nucleic acids.
2___Function of the protein changes with the shape.
3___Amino acids differ from each other in the amino groups.
4___All amino acids have carboxyl group and amino group.
5___Usually enzymes are proteins.

3 (individual work). Answer questions.
A. What is an amino acid?
B. What are differences between four levels of proteins?

Proteins are a class of macromolecules that perform a diverse range of functions for the cell. They help in metabolism by providing structural support and by acting as enzymes, carriers, or hormones. The building blocks of proteins (monomers) are amino acids. Each amino acid has a central carbon that is linked to an amino group, a carboxyl group, a hydrogen atom, and an R group or side chain. There are 20 commonly occurring amino acids, each of which differs in the R group. Each amino acid is linked to its neighbours by a peptide bond. A long chain of amino acids is known as a polypeptide.Proteins are organised at four levels: primary, secondary, tertiary, and quaternary. The primary structure is the unique sequence of amino acids. The local folding of the polypeptide to form structures such as the α helix and β-pleated sheet makes the secondary structure. The overall three dimensional structure is the tertiary structure. When two or more polypeptides combine to form the complete protein structure, the configuration is known as the quaternary structure of a protein. Protein shape and function are linked; any change in shape caused by changes in temperature or pH may lead to protein denaturation and a loss in function.

4 (individual work). This is the key vocabulary for the Proteins. Do you know meaning of these words and phrases? Use a dictionary to match the words with their translation.

to coil

to denature

to spin

to fold

to dissolve

velocity

to untangle

5 (individual work). Answer questions after watching the Proteins video

1. Why would large proteins be harder to untangle and refold than smaller ones?

1. Explain why raw egg white is liquid while boiled egg white is solid and bouncy?

6 (team work). Discuss answers with your team.