Proteins

What is a peptide bond?

• Bond that holds two amino acids together.
• A bond that holds hydrogen and oxygen molecules together.
• A bond that holds the phosphate group of one nucleotide and a sugar of a neighboring nucleotide.
• A bond that is formed by the sharing of electrons.

How many different amino acids are there?

• 15
• 20
• 25
• 30

Enyzmes are a very important type of protein used to

• Build bones in skeleton
• Send hormonal signals throughout body
• Speed up chemical reactions
• Photosynthesize glucose in plants

What is a protein: 

• A polymer composed of many sugars.
• A polymer composed of many amino acids. 
• A polymer composed of fatty acids. 
• A polymer composed of nucleotides. 

The diagram shows the structure of an amino acid. Which type of molecule is formed from amino acids?

• lipids
  
• proteins
  
• carbohydrates
  
• nucleic acids
  

The structure of proteins can be changed by environmental factors such as temperature or pH.

• True
• False

The diagram shows a bond forming between two amino acids. What is the name of this reaction?

• Dehydration Synthesis
• Hydrolysis
• Pepysis
• Oxidation

Cells must produce many different enzymes because

• enzymes are quickly used up
• most cellular reactions require a specific, unique enzyme
• They have to have some way to use up the protein that they consume
• enzymes are not very effective at speeding up reactions

Enzymes are...

• Proteins
• Nucleic Acids
• Sugars
• Lipids

What elements make up amino acids?

• Carbon, hydrogen and oxygen only
• Carbon, hydrogen, oxygen and nitrogen only
• Carbon, hydrogen and phosphorus only
• Carbon, hydrogen, nitrogen and oxygen; and sometimes also sulfur