Chapter 5 - Proteins Flashcards
Protos
“primary importance”
-protos wine
-protoss game
-protos wagen (german car company)
Protein
-part of every cell and a source of energy in your body
-builds and repairs tissues (like skin and muscle)
-makes vital substances as antibodies, insulin
-found in: hard boiled eggs, hummus, edamame, milk, tuna, nuts, chickpeas, etc
-complex macromolecules from combination of 20 types of amino acids: basic building block of protein
Essential Amino Acids
-8/20 amino acids are essential, and found in food because can’t be made by the body
-indispensable
Nonessential Amino Acids
-12/20 amino acids are nonessential, and can be made by the human body (with enough C, N, H, O
-dispensable
Complete Proteins
proteins with only essential amino acids
Incomplete Proteins
missing at least 1 essential amino acid
Methionine
essential AA
-coded by codon AUG, called start codon
-1st AA used to build protein chain
Central Dogma Process
process to synthesize AA from DNA (info for proteins)
1.) Replicate DNA (requires deoxyribose, N base pair, Phosphate G)
2.) Transcription: make DNA into RNA
3.) Translation: make RNA into AA
Hemoglobin
protein
-bonds with and carries ozygen molecules
Functions of Body Proteins
-enzymes: speeds up chemical reaction
-hormones: chemical messenger
-antibody: made to protect from foreign substances
-fluid balance: pumps molecules across cell membranes and attracts water
-transport key substances (CO2, vitamins, minerals) to target cells in body
-acid-base balance
-structural and mechanical
AA Structure
-20 AAs commonly found in proteins, each with a different R group that determines chemical nature
-grouped by polarity or charge
1st AA Structure Grouping
Nonpolar, Aliphatic R group
2nd AA Structure Grouping
Polar, Noncharged - can be both because it is easily charged
3rd AA Structure Grouping
Positively Charged
4th AA Structure Grouping
Negatively Charged
5th AA Structure Grouping
Nonpolar Aromatic (ring structure)
Which AA grouping is Hydrophobic?
1 and 5
Amphipathic
both polar and nonpolar
Amino Acids to Protein
-AAs link is specific sequences to form standards of proteins (peptides) up to 100 of AAs long
-AA joined to the next with a peptide bond
-2 AA = dipeptide
-3 AA = tripeptide
-4-10 AA = oligopeptide
-> 10 AA = polypeptide
-Peptide bond formation done with dehydration synthesis - carboxyl group bonds with amino group
Aldose
Carboxyl Group at the end
Ketose
Carboxyl Group in the middle
Primary Polypeptides
a long chain of polypeptides only
-no function
Folding
Polypeptides need a specific structure to function
-creates 3D shape which determines function and interaction with other molecules
Secondary Polypeptides
alpha helix or beta sheet form because of Hydrogen bonding between a Carbonyl and Amino Group
-no function!
Tertiary Polypeptides
-AA helices/sheets are folded over eachother to form 3D folding pattern
-variety of chemical interactions determine proteins’ tertiary structure: hydrophobic, ionic bond, hydrogen bond, disulfide linkages
-some function
Quaternary Polypeptides
2+ proteins in T structure are associated with each other (2+ tertiary structures)
-all of these proteins are functional
Denaturation
-alteration in 3D structure, causes unfolded polypeptide chain that usually lacks biological activity (destabilizing proteins shape)
-usually caused by acids, bases, enzymes, heat, and others
-can be reversed (structure reformed) as renaturation
Mutation
changes in DNA - AA
Enzyme and Substrate Example
Amylase - Amylose
Lipid - Lipase
-Protein - Protease
Sickle Cell Anemia
-change in the nucleotide sequence of gene’s coding – diff AA is added with changes in protein structure and function
-hemoglobin beta chain in protein structure and function
-dramatically decreases life expectancy
-single AA substitution leads to SCA
-normal hemoglobin: AA at position 7 = glutamate
-SC hemoglobin: valine replaces glutamate which forms into long fibers that distort into disc-shaped red blood cells –> giving them sickle shape which clogs blood vessels and can lead to : breathlessness, dizziness, headaches, abdominal pain
Enzymes
proteins that catalyze reactions in our body (like dehydration synthesis and hydrolysis)
-work like lock and key: can build or break molecules down; not all keys work on any lock
