Macromolecules: Proteins

Bell work Why does your body need proteins to function?

Objectives Explain why a protein is a polymer List the different functions of proteins Describe the four levels of protein structure

Key Terminology Amino acid Enzymes Peptide Bond Primary Structure Secondary Structure Tertiary Structure Quaternary Structure

Proteins Polymers of amino acids Have diverse shapes & functions

Diverse Functions of Proteins Include: Anchor provide support & protection Transporter move ions and small molecules across membranes

Diverse Functions of Proteins Include: Enzyme act as catalysts to speed up chemical reactions Receptor bind chemical signals, like hormones

Think-Pair-Share Describe an example of a protein and its function. Be ready to share 3. Think-pair-share teacher presents a question teacher gives wait time for student to form answer teacher instructs students to share their answer with a partner teacher calls on non-volunteers to share with the class 3 8

Structure of an Amino Acid Amino acids have basic structure as shown R group varies between amino acids 20 different type of R groups 20 different amino acids

Amino acids linked together by a Peptide Bond is a covalent bond

Four levels of Protein Structure Primary structure order of amino acids each protein has a unique sequence of amino acids Cannot function as a long chain of amino acids must continue to fold into a unique shape Secondary structure amino acids within the chain become twisted or folded

Four Levels of Protein Structure Tertiary structure chain folds upon itself to 3-D structure Quaternary structure May have more than one protein chain Multiple chains link together

Summary of the 4 levels

Example: Hemoglobin Function: transport oxygen in blood Shape: “globular” with binding sites for 4 oxygen molecules

Example: Hemoglobin Has Quaternary Structure Made of 2 alpha subunits and 2 beta subunits

Think-Pair-Share Be ready to share Proteins have diverse functions. What is it about proteins that allow them to be so diverse? Be ready to share 3. Think-pair-share teacher presents a question teacher gives wait time for student to form answer teacher instructs students to share their answer with a partner teacher calls on non-volunteers to share with the class 16

Minute Paper You have one minute on your note-taker to write down key points of today’s lesson. Be ready to share. 29. Minute paper or Quick Write teacher provides a prompt from the lesson students have one minute to write down a summary of the key points students compare with a partner teacher uses a strategy to check all 17