1Proteins are made from long chains of what?
Amino acids
2What is formed when two amino acids join together?
A dipeptide
3What is a polypeptide?
A chain of more than two amino acids
4What makes up the structure of amino acids?
A carboxyl group, an amine group, and an R group
5How many different amino acids are there in nature?
Twenty
6What do all living things share?
A bank of 20 amino acids
7How are polypeptides formed?
By condensation reactions
8What type of bond forms between amino acids?
Peptide bonds
9What happens during the digestion of proteins?
The reverse reaction occurs, breaking peptide bonds
10What are the four structural levels of proteins?
Primary, secondary, tertiary, and quaternary
11What defines the primary structure of a protein?
The sequence of amino acids in the polypeptide chain
12What occurs in the secondary structure of proteins?
Hydrogen bonds cause the chain to coil or fold
13What forms the tertiary structure of proteins?
Further coiling and folding of the polypeptide chain
14What are disulfide bridges?
Bonds formed between sulfur atoms in cysteine amino acids
15What is the quaternary structure of a protein?
The arrangement of multiple polypeptide chains
16What is one function of enzymes?
Roles in metabolism
17What are antibodies made of?
Two light polypeptide chains and two heavy polypeptide chains
18What do transport proteins do?
Transport ions and molecules across membranes
19What are structural proteins characterized by?
Strong, long polypeptide chains lying parallel to each other
20What is the first step of the Biuret test for proteins?
Add sodium hydroxide solution to make it alkaline
21What indicates the presence of protein in the Biuret test?
The solution turns purple
22If there’s no protein present in the Biuret test, what color will the solution remain?
Blue