Chapter 16: Amino Acids and Proteins Flashcards
____ in the body are polymers made from 20 different amino acids.
proteins
Proteins in the body are _______ made from 20 different amino acids
polymers
Proteins form structural components such as:
Cartilage, muscles, hair, and nails
“form structural components such as cartilage, muscles, hair, and nails” this describes what?
Protein
What is the function of protein?
function as enzymes to regulate biological reactions such as digestion and cellular metabolism
Proteins function as ______ to regulate biological reactions such as digestion and cellular metabolism
enzymes
Proteins such as _______ and _______ transport oxygen in the blood
hemoglobin and myoglobin
“provide structural components” which class of protein does this describe?
Structural
“Makes muscles move” which class of protein does this describe?
Contractile
“Store nutrients” which class of protein does this describe?
storage
“Regulate body metabolism and the nervous system” which class of protein does this describe?
Hormone
” Catalyze biochemical reactions in the cells” which class of protein does this describe?
Enzyme
“Recognize and destroy foreign substances” which class of protein does this describe?
Protection
What is the function of the protein class structural?
Provide structural components
What is the function of the protein class contractile?
Make muscles move
What is the function of the protein class transport?
Carry essential substances throughout the body
What is the function of the protein class storage?
Store nutrients
What is the function of the protein class hormone?
Regulate body metabolism and the nervous system
What is the function of the protein class enzyme?
Catalyze biochemical reactions in the cells
What is the function of the protein class protection?
Recognize and destroy foreign substances
“carry essential substances throughout the body” which class of protein does this describe?
Transport
“Collagen is in the tendons and cartilage, and keratin is in hair, nails, skin, and wool.” Which protein class does this refer to?
Structural
“Myosin and actin contract muscle fibers” Which protein class does this refer to?
Contractile
“Hemoglobin transports oxygen. Lipoproteins transport lipids” Which protein class does this refer to?
Transport
“Casein stores protein in milk. Ferritin stores iron in the spleen and liver. Which protein class does this refer to?
Storage
“insulan regulates blood glucose level. Growth hormone regulates body growth.” Which protein class does this refer to?
Hormone
“Sucrase catalyzes the hydrolysis of sucrose. Trypsin catalyzes the hydrolysis of proteins” Which protein class does this refer to?
Enzyme
“immunoglobins stimulate immune responses” which protein class does this refer to?
Protection
Amino acids are the “___________”
building blocks of protein
Do amino acids have a central carbon called the a-carbon bonded to two functional groups, an ammonium (-NH3+) and a carbonyl group (OH-C=O)?
No, amino acids have an ammonium, yes, but not a carbonyl. It’s a carboxylate (-COO-)
The central carbon atom in amino acids is bonded to a _____ atom and the R group or side chain in addition to the ________ and ______ groups
hydrogen (H) and in addition to the ammonium and carboxylate groups
What does the central carbon atom in an amino acid need to have to be considered an amino acid?
The central atom needs to be bonded to a hydrogen atom, and R or side group, and the ammonium group with the carboxylate group. Ammonium is the -NH3+ group and the carboxylate is the C=O–O- group, (-coo-)
Hydrophobic is _______ and hydrophilic is ______
nonpolar; polar
True or false, a hydrophobic amino acid is polar.q
False, phobic amino acids are non polar. Phobia of water.
How can you tell if an amino acid is non polar or polar?
You have to look at the side chains. Side chains with an NH2 (or polar and ionic) group will be polar, and Side chains with hydrocarbon atoms will be non polar.
An amino acid has a side chain of CH3-CH-CH3. is this AA polar or non polar?
Non polar
An amino acid has a side chain of O=C-CH2-NH2. Is this AA polar or non polar?
Polar
An amino acid is non polar with a side chain of all hydrocarbons. An Amino acid is also non polar when the R group is H, ____, or _____
Alkyl(CH3-CH-CH2 for example, or CH3-S-CH2) or aromatic(benzene ring)
An amino acid is polar when the R group is a ______, ______, or an amide
Hydroxyl(OH), thiol(SH, or an amide(NH2)
When is an amino acid acidic?
when the R group is a carboxylate (O=C-O=)
When is an amino acid basic?
When the R group is an amine(Ch2-NH2), which ionizes to give an ammonium ion.
An amino has to have a carbon attached to an -NH3+, an O=C-O-, and an H group. Only the fourth component can differ for every amino acid, and that is the ____ group
R group.
How do you name long ass amino acids?
A three letter or one letter abbreviation derives from its name
What is a peptide bond?
It is an amide bond that forms when the carboxylate group of one amino acid reacts with the ammonium group of the next amino acid
A _____ ____ bond is an amide bond that forms when the O=C-O- group of one amino acid reacts with the -NH3+ group of the next amino acid
Peptide bond
Two or more amino acids bonded becomes a ______
peptide
Two amino acids are called a ______
dipeptide
Three amino acids are called a______
tripeptide
Four amino acids are called a ______
tetrapeptide
How many essential amino acids are there?
9
Can essential amino acids be synthesized in the body?
No
How do you obtain the essential amino acids necessary for the body?
Through protein in your diet
How many amino acids can be synthesized in the body?
11 out of 20 (the other 9 are essential)
Why do vegetarians need to be careful with their diet?
Complete proteins are found in eggs, milk, meat, and fish, so vegetarians need to make up for the proteins missing in meat and fish by finding them in other food sources. Incomplete proteins are found in other plant sources so a vegetarian may need need to eat 4 or 5 different plant sources to make up for all the complete protein found in just meat alone.
A protein is a polypeptide of ___ or more amino acids
50
The _____ structure of a protein is the particular sequence of amino acids held together by peptide bonds
primary
Does Insulin have a primary or secondary structure?
Primary
____ was the first protein to have its primary structure determined
insulin
The alpha helix of a secondary protein structure has a coiled shape. How?
Hydrogen bonds between the oxygen of the C=O and the hydrogen of the N-H in the next turn.
What shape forms when there are hydrogen bonds between the oxygen of the C=O and the hydrogen of the N-H group?
A-helix
In the secondary structure of a ____-____ _____, hydrogen bonds form between the carbonyl oxygen atoms and hydrogen atoms in the amide groups bending the polypeptide chain into a sheet
beta-pleated sheath
In the secondary structure of a ____ _____, three polypeptide chains are woven together
triple helix
In the secondary structure of a triple helix, ______ bonds hold the chains together, giving the polypeptide the added strength typical of structural protein
hydrogen
The _____ _____ of a protein is an overall three dimensional shape caused by interactions of different parts of the chain
tertiary structure
The _____ _____ of a protein is determined by cross links, the attractions and repulsions between the ___ groups of the amino acids in a peptide chain
tertiary structure; R groups
Interactions between amino acid R groups fold a protein into a specific three-dimensional shape called it’s _____ _____
tertiary structure
Hydrophobic interactions between two non polar amino acids is important in forming which structure level of a protein?
Tertiary
Hydrophilic interactions between the external aqueous environment and the R groups of polar amino acids is important in forming which structure level of a protein?
Tertiary interactions
____ _____, ionic bonds between ionized R groups of basic and acidic amino acids is important in the formation of tertiary structures
salt bridges
____ _____ between H of a polar R group and the O or N of another amino acid plays an important part in in creating the tertiary structure of a protein
hydrogen bonds
____ ____ —S—S— between the —SH groups of cysteine amino acids is important in the creation of tertiary structure proteins
disulfide bonds
“Polypeptide chains held side by side by H bonds” this indicates which type of protein structure? (primary/alpha helix/beta-pleated sheet/triple helix)
Beta pleated
“Sequence of amino acids in a polypeptide chain” this indicates which type of protein structure? (primary/alpha helix/beta-pleated sheet/triple helix)
Primary
“Corkscrew shape with H bonds between amino acids” this indicates which type of protein structure? (primary/alpha helix/beta-pleated sheet/triple helix)
Alpha helix
“Three peptide chains woven like a rope” this indicates which type of protein structure? (primary/alpha helix/beta-pleated sheet/triple helix)
Triple helix
The ______ _____ of a protein is the combination of two ore more protein units
quaternary structure
The _____ ____ of a protein consists of four polypeptide chains as subunits in ______
quaternary structure; hemoglobin
The _____ ____ of a protein is stabilized by the same interactions found in tertiary structures
quaternary structure
In the ribbon structure of ______, the Q structure is made up of how many polypeptide subunits?
Hemoglobin; four (
What is the function of the heme groups in hemoglobin?
To bind oxygen
_______ involves the disruptions of bonds in the secondary, tertiary, and quaternary protein structures
Denaturation
Denaturation by ____ and ______ compounds causes H bonds to break apart which disrupts hydrophobic interactions?
Heat and organic compounds
Denaturation by ____ and _____ causes H bonds to break between polar R groups and disrupt ionic bonds
acids and bases
Denaturation by heavy metal ions react with __-__ bonds to form solids
S-S
Denaturation by _____, such as whipping, that stretches peptide chains until bond breaks
agitation
Denaturation of ____ occurs when an egg is cooked
protein
What are enzymes?
Proteins that act as biological catalysts
Proteins that act as biological catalysts are called what?
Enzymes
What is the small region on an enzyme called that is responsible for binding a substrate and catalyzing a specific reaction for that substrate
Active site
What is an active site?
A small region that binds a substrate and catalyzes a specific reaction for that substrate
_____ catalyze nearly all the chemical reactions taking place in the cells of the body
enzymes
Do enzymes increase or decrease the rate of reaction by lowering the energy of activation for the reaction?
Increase, which really honestly sounds ass backwards but okay
The name of an enzyme is derived by…
replacing the end of the name of the reaction with the suffix -ase
Sometimes the name of an enzyme identifies the _____ substance
reacting (sucrase catalyzes the reaction of sucrose)
Sometimes the name of an enzyme describes the compound or reaction that is ______
catalyzed (ex: oxidase catalyzes an oxidation reaction)
Sometimes the name of an enzyme is simply a _____ name
common. (particularly digestion enzymes i.e pepsin and trypsin)
What does the active site of an enzyme contain that binds the substrate?
The amino acid R groups
The active site _____ _____ when the reaction is complete
releases products
The E-S complex stands for:
Enzyme-Catalyzed reaction
What happens first in an E-S reaction?
A substrate attaches to the active site
What happens second in an E-S reaction?
An enzyme-substrate complex forms
What happens in the 3rd step of an E-S reaction after the complex forms?
The reaction occurs and the products are released.
Is an enzyme used over and over again or is it done after a reaction and the products are released?
An enzyme is used over and over again.
Binding of a substrate occurs when it reacts with the ____ ____ within the active site
amino acids
Which enzyme model has active sites with rigid, non flexible shapes?
Lock-and-Key
Which enzyme model pertains to enzymes that bind only substrates that EXACTLY fit the active site like a “lock”
lock and key
Which enzyme model’s substrate is the key to unlocking the reaction?
Lock and key
The problem with the lock and key model was what?
It did not include the flexibility of the tertiary shape of an enzyme and the way the active site can adjust to the shape of a substrate
Is the induced fit model the exact opposite of the lock and key model?
yes
Which enzyme model pertains to enzymes that are flexible and adjust to the shape of the active site in order to bind the substrate?
induced-fit model
Which enzyme model pertains to enzymes where the range of substrate specificity increases?
Induced-fit
Which enzyme model pertains to enzymes that allow shape changes which improve catalysis during reaction?
Induced-fit
In the ____-___ model, substrate and enzyme work together to acquire a geometrical arrangement that lowers the activation energy of the reaction
induced-fit
______ are different forms of an enzyme that catalyze the same reaction in different cells or tissues of the body
isoenzymes
______ consist of quaternary structures with slight variations in the amino acids in the polypeptide subunits
Isoenzymes
Name the factors that affect the activity of an enzyme
Temperature, pH, and substrate concentration
Enzymes are most active at optimum temperature which is ____ celsius
37
At which temperature higher than the optimum temperature do enzymes begin to lose activity due to denaturation?
50 celsius
What is the optimum pH of enzyme activity?
7.4
Low and high pH’s do what to enzyme activity?
lower the activity
When the pH is too high or too low, which decreases enzyme activity, which protein structure is disrupted?
Tertiary
_________ are molecules that cause a loss of catalytic activity
Inhibitors
_______ prevent substrates from fitting into the active sites
inhibitors
“has a structure similar to that of the substrate” which inhibition is this?
Competitive
“competes with the substrate for the active site” which inhibition is this?
competitive
“Has its effect reversed by increasing the substrate concentration” which inhibition is this?
competitive
“Has a structure that is much different than that of the substrate” which inhibition is this?
Noncomp.
“Binds to an enzyme at a site other than the active site and distorts the shape of the enzyme by altering the shape of the active site” Name the inhibition
Noncompetitive
“prevents the binding of the substrate” Name the inhibition.
non competitive
“cannot have its effect reversed by adding more substrate” Name the inhibition
non comp
“Is a molecule that causes the enzyme to lose all activity” Name the inhibition
irreversible
“is often a toxic substance that destroys enzymes” Name the inhibition
irrev.
“Usually forms a covalent bond with an amino acid side chain, preventing catalytic activity” name the inhibition
irrev.
“May be a nerve gas, an insecticide, or an antibiotic” Name the inhibition
irrev.
