Ch. 3.2 - Proteins Flashcards
1
Q
proteins (4)
A
- polymers made from various combinations of 20 amino acids
- most diverse type of biomolecule
- all enzymes that catalyze reactions
- each has a carboxyl group (COOH) and amino group (NH3), that tend to be ionized at cellular pH
2
Q
4 levels of structural organization of proteins
A
primary, secondary, tertiary, quaternary
3
Q
amino acids (3)
A
- building blocks of proteins
- linked via dehydration synthesis between the carbon of the carboxyl group of one molecule and the amino group of another -> forms peptide bond
4
Q
sample amino acid
A
central carbon=alpha C is bonded to an amino group on one side, a carboxyl group on another side, a H on the 3rd side, and a functional R group on the 4th side
5
Q
R group (2)
A
- only difference between the 20 a2 is the R group
- can be hydrophobic (more insoluble) or hydrophilic (soluble)
6
Q
functions of proteins (7)
A
- enzymes (catalyze/regulate chemical reactions)
- transport (embedded molecules transport across CM)
- defensive (antibodies)
- signal (hormone and other chemical messengers that help coordinate activities and reactions in the body)
- receptor (built into CM and help transmit and receive signals between different body cells)
- contractile (muscle cells)
- structural (fibrous proteins found in hair and collagen that make up connective tissue)
7
Q
quaternary protein structure (2)
A
- involves 2+ 3D tertiary proteins and “sticking” them together to form a larger protein
- many enzymes and transport proteins have 2+ parts
8
Q
proteins gone bad (2)
A
- becomes denatured when they lose their 3D shape and their function
- denaturation can be caused by acids, salts, or heat and may be reversible
9
Q
nucleic acids (5)
A
- found in nucleus
- responsible for gene transfer
- ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)
- monomers
- nucleotide
10
Q
monomers
A
nucleotides, joined by dehydration synthesis
11
Q
3 parts of nucleotide
A
5C sugar (ribose or deoxyribose), PO4 group, nitrogen containing base
12
Q
DNA/RNA molecules (7)
A
- DS joins the sugar of one nucleotide to the phosphate group of the next monomer
- nitrogenous bases are not part of the backbone
- RNA tends to be single stranded
- DNA is a double stranded helix
- because DNA cannot get out of the nucleus, its information is transcribed to RNA
- RNA can then leave the nucleus and interact with the “protein making machinery” of the cell where DNA code is translated into proteins
13
Q
DNA (2)
A
- codes for everything the cell makes and does
- responsible for the primary structure of proteins
14
Q
the genetic code (3)
A
- cytosine, guanine, adenine, thymine
- strands are joined by H-bonds between the bases
- in RNA thymine is replaced with uracil, so A pairs with U
15
Q
fats - triglycerides
A
- made from glycerol (3C alcohol) and 3 long chain fatty acids
- fatty acids
- function: long term energy storage
- carboxyl end of one fatty acid joins with OH group of the glycerol via DS to form an ester bond
