Ch. 7 Proteins
non-essential amino acid
A healthy human body can make 11 of the 20 amino acids that are in the proteins. these compounds are the non-essential amino acids.
Peptides
are small chains of amino acids that usually contain fewer than 15 amino acids
tRNA (transfer ribonucleic acid)
conveys specific amino acids, one at a time, to the ribosomes. At the ribosomes, the amino acid from tRNA is added to the last amino acid, causing the peptide chain to grow longer.
A poly peptide
forms when two or more amino acids join to form a chain
Essential-amino acids
must be supplied by foods because the body cannot synthesize them or make enough to meet its needs.
A protein in red blood cells, hemoglobin, is comprised of four polypeptide chains coiled together. This shape makes hemoglobin very good at transporting _______.
oxygen
what is a chemical attraction between the acid group of one amino acid and the amino group of another amino acid?
peptide bond
An amino acid can connect to another amino acid by a
peptide bond - a chemical attraction between the acid group of one amino acid & the amino group of another amino acid
a vegetarian only eats
plant food
Insulin
protein hormone (made by the cells of the pancreas) that helps to lower blood sugar
The ________ of a protein is important because it influences the compound's activity in the body.
shape
Protein synthesis
- DNA unwinds exposing a gene - the gene undergoes transcription, forming messenger RNA - mRNA transfers the information from the nucleus to ribosomes - the ribosomes "read" the messenger RNA - RNA molecule conveys a particular amino acid to the ribosome - at the ribosome, the amino acid attaches to the peptide chain
If the DNA code is faulty
- Incorrect mRBA will be produced - the polypeptide chain will be incorrect - Ribosomes won't read the correct message - the wrong amino acid will be inserted into the chain consistently forming an abnormal polypeptide * cause: genetic defects, having devastating, even deadly, effects on the organism
A crescent shaped blood cell is indicative of:
- genetic disorder - sickle cell anemia - faulty DNA code
Denaturation
A protein undergoes _______ when it is exposed to various conditions that alter the macronutrient's natural folded and coiled shape. Heat also causes the proteins in foods to unfold. Whipping or exposing them to alcohol or acid are other treatments often used during food preparation that denature proteins
Which cells do not contain protein?
None, all cells contain some protein
What is the term for the chemical bond formed between amino acids in a protein?
Peptide Bond
what happens to protein production when the supply or "pool" of amino acids does not have one or more of the essential amino acids needed for constructing the protein?
Production of the protein stops