TEST 6 Flashcards
The basic unit of contraction in a skeletal muscle is?
a) Myofibril
b) Sarcomere
c) Tendon
d) Myosin
Sarcomere
The ___________ is the contractile protein found in the thick filaments of a sarcomere.
a) Actin
b) Tropomyosin
c) Myosin
d) Troponin
Myosin
The _______ is a specialized endoplasmic reticulum found in skeletal muscle cells.
a) Sarcoplasmic reticulum
b) Golgi apparatus
c) Mitochondria
d) Nucleus
Sarcoplasmic reticulum
The _______ is a thin filament protein that covers the active sites on actin molecules in a relaxed muscle fiber.
a) Myosin
b) Tropomyosin
c) Troponin
d) Sarcomere
Tropomyosin
The __________ is the regulatory protein that binds calcium ions and initiates muscle contraction.
a) Actin
b) Tropomyosin
c) Myosin
d) Troponin
Troponin
The __________ is the region of a sarcomere where actin and myosin filaments overlap.
a) Z-line
b) M-line
c) H-zone
d) A-band
H-zone
The __________ is the protein that connects the Z-lines and helps stabilize the sarcomere during contraction.
a) Actin
b) Titin
c) Myosin
d) Nebulin
Titin
The __________ is the thin filament protein that anchors actin to the Z-line.
a) Tropomyosin
b) Myosin
c) Nebulin
d) Dystrophin
Tropomyosin
The __________ is the area in the center of the sarcomere that contains only myosin filaments.
a) I-band
b) H-zone
c) A-band
d) Z-line
H-zone
The __________ is the structure that connects the muscle to the bone.
a) Tendon
b) Ligament
c) Cartilage
d) Fascia
Tendon
The __________ is the neurotransmitter released by motor neurons to initiate muscle contraction.
a) Dopamine
b) Serotonin
c) Acetylcholine
d) Norepinephrine
Acetylcholine
The __________ is the structure where the motor neuron and muscle fiber meet.
a) Neuromuscular junction
b) Synaptic cleft
c) Sarcolemma
d) Sarcoplasmic reticulum
Neuromuscular junction
The __________ is the structural protein that surrounds individual muscle fibers.
a) Endomysium
b) Perimysium
c) Epimysium
d) Sarcolemma
Endomysium
The __________ is the plasma membrane of a muscle fiber.
a) Epimysium
b) Endomysium
c) Sarcolemma
d) Perimysium
Sarcolemma
The __________ is the functional unit of a muscle fiber.
a) Sarcomere
b) Myofibril
c) Sarcoplasm
d) T-tubule
Sarcomere
The __________ is the storage form of glucose in skeletal muscle.
a) Glycogen
b) Glucagon
c) Insulin
d) Glucose-6-phosphate
Glycogen
The __________ is the type of muscle fiber that is adapted for aerobic endurance activities.
a) Type I (slow-twitch)
b) Type IIa (fast-twitch oxidative)
c) Type IIb (fast-twitch glycolytic)
d) Type III (intermediate)
Type I (slow-twitch)
The __________ is the protein responsible for releasing calcium ions from the sarcoplasmic reticulum.
a) Actin
b) Tropomyosin
c) Myosin
d) Ryanodine receptor
Ryanodine receptor
The __________ is the energy molecule used by muscle fibers to power contraction.
a) ATP
b) ADP
c) AMP
d) GTP
ATP
The __________ is the enzyme that breaks down acetylcholine in the synaptic cleft.
a) Acetylcholinesterase
b) Monoamine oxidase
c) Cholinesterase
d) Adenosine triphosphatase (ATPase)
Acetylcholinesterase
The specific area on the muscle fiber where the motor neuron releases acetylcholine is known as the __________.
a) Sarcolemma
b) T-tubule
c) Sarcoplasmic reticulum
d) Synaptic cleft
Synaptic cleft
Acetylcholine binds to receptors on the __________, which triggers an electrical impulse in the muscle fiber.
a) Sarcolemma
b) T-tubule
c) Sarcoplasmic reticulum
d) Synaptic cleft
Sarcolemma
The electrical impulse generated in the muscle fiber travels deep into the muscle fiber via structures called __________.
a) Sarcomeres
b) Actin filaments
c) Myosin filaments
d) T-tubules
T-tubules
The presence of the electrical impulse in the T-tubules triggers the release of __________ from the sarcoplasmic reticulum.
a) Calcium ions
b) Sodium ions
c) Potassium ions
d) Chloride ions
Calcium ions
Calcium ions released from the sarcoplasmic reticulum bind to a regulatory protein called __________.
a) Actin
b) Tropomyosin
c) Myosin
d) Troponin
Troponin
The binding of calcium ions to troponin causes a conformational change, which allows __________ to interact with __________.
a) Actin; tropomyosin
b) Actin; myosin
c) Myosin; tropomyosin
d) Myosin; actin
Actin; myosin
The interaction between actin and myosin leads to the formation of cross-bridges, and subsequent __________ of the muscle fiber.
a) Relaxation
b) Contraction
c) Elongation
d) Shortening
Contraction
Acetylcholine is rapidly broken down by the enzyme acetylcholinesterase to terminate muscle stimulation at the neuromuscular junction. True or false?
True
The release of calcium ions from the sarcoplasmic reticulum is an essential step in muscle contraction. True or false?
True
T-tubules play a crucial role in transmitting the electrical signal from the motor neuron to the deep regions of the muscle fiber. True or false?
True
Troponin is a thin filament protein that directly interacts with myosin during muscle contraction. True or false?
False
The neuromuscular junction is responsible for transmitting sensory information from the muscle back to the central nervous system. True or false?
False
The binding of calcium ions to troponin causes tropomyosin to shift, exposing the active sites on actin for myosin binding. True or false?
True
The neuromuscular junction allows for precise control and coordination of muscle movements. True or false?
True
The neurotransmitter acetylcholine is released into the synaptic cleft by the muscle fiber. True or false?
False
The action potential generated by the motor neuron triggers the release of acetylcholine from the motor end plate. True or false?
True
The release of calcium ions from the sarcoplasmic reticulum is stimulated by the presence of acetylcholine at the neuromuscular junction. True or false?
False
The neuromuscular junction is a one-way communication system, with signals traveling only from the motor neuron to the muscle fiber. True or false?
True
The rise of intracellular calcium that blocks the actin and myosin results in a state of ____________
Rigor mortis
The autoimmune disorder where patient develops antibodies against acetylcholine receptors is called?
Myasthenia Gravis
Resting membrane potential refers to the electrical potential difference across the __________ of a neuron.
a) Cytoplasm
b) Cell membrane
c) Axon
d) Dendrites
Cell membrane
The resting membrane potential is typically around __________ millivolts in a neuron.
a) -70
b) -40
c) 0
d) +40
-70
The resting membrane potential is primarily maintained by the uneven distribution of __________ ions inside and outside the neuron.
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)
Potassium (K+)
The movement of ions across the cell membrane is regulated by __________.
a) Neurotransmitters
b) Ion channels
c) Vesicles
d) Synapses
Ion channels
During the resting membrane potential, there is a higher concentration of __________ ions outside the neuron compared to inside.
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)
Sodium (Na+)
The movement of potassium ions out of the cell is facilitated by __________ channels.
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)
Potassium (K+)
The movement of sodium ions into the cell is regulated by __________ channels.
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)
Sodium (Na+)
The resting membrane potential is a dynamic state and can change in response to various stimuli. True or false?
False
The sudden change in the electrical potential across the cell membrane, resulting in the generation of an action potential, is known as __________.
a) Repolarization
b) Hyperpolarization
c) Depolarization
d) Resting potential
Depolarization
Action potential is generated when the membrane potential reaches the __________ threshold.
a) Resting
b) Hyperpolarized
c) Depolarized
d) Repolarized
Resting
The rapid depolarization phase of the action potential is primarily caused by the influx of __________ ions.
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)
Sodium (Na+)
The repolarization phase of the action potential is primarily caused by the efflux of __________ ions.
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)
Potassium (K+)
The return of the membrane potential to its resting state is known as __________.
a) Repolarization
b) Hyperpolarization
c) Depolarization
d) Resting potential
Repolarization
The all-or-none principle states that once an action potential is initiated, it will propagate along the entire length of the __________.
a) Dendrites
b) Cell body
c) Axon
d) Synapse
Axon
The speed of action potential conduction can be increased by the presence of __________ along the axon.
a) Myelin sheath
b) Nodes of Ranvier
c) Neurotransmitters
d) Synaptic vesicles
Myelin sheath
Action potential propagation can occur in both directions along an axon. True or false?
False
The brief period following an action potential during which the neuron is temporarily unresponsive to further stimulation is known as the __________ period.
a) Refractory
b) Resting
c) Depolarization
d) Hyperpolarization
Refractory
Action potentials occur continuously in neurons, even during the resting state. True or false?
False
Saltatory conduction refers to the “jumping” of the action potential between __________ along a myelinated axon.
a) Neurotransmitters
b) Nodes of Ranvier
c) Synaptic vesicles
d) Dendrites
Nodes of Ranvier
The movement of ions during an action potential is primarily governed by the principles of __________.
a) Diffusion and osmosis
b) Active transport
c) Electrostatics and electrochemical gradients
d) Endocytosis and exocytosis
Electrostatics and electrochemical gradients
The __________ phase of the action potential involves a temporary hyperpolarization of the membrane potential.
a) Depolarization
b) Repolarization
c) Overshoot
d) Afterhyperpolarization
Afterhyperpolarization
The __________ is the critical voltage level that must be reached to trigger an action potential.
a) Threshold
b) Resting potential
c) Hyperpolarization
d) Repolarization
Threshold
Action potentials are typically longer in duration compared to the resting membrane potential. True or false?
False
The movement of ions during an action potential is primarily driven by __________.
a) Active transport pumps
b) Diffusion
c) Osmosis
d) Facilitated diffusion
Diffusion
The __________ is the time period during which a second action potential cannot be generated, regardless of the strength of the stimulus.
a) Absolute refractory period
b) Relative refractory period
c) Resting period
d) Threshold period
Absolute refractory period
The resting membrane potential of a neuron is maintained by the constant activity of sodium-potassium pumps. True or false?
True
The movement of ions during an action potential occurs due to changes in the __________.
a) Concentration gradient
b) Electrical gradient
c) Both concentration and electrical gradients
d) None of the above
Both concentration and electrical gradients
Action potentials can only occur in neurons and not in other types of cells. True or false?
False
The __________ period refers to the time during an action potential when the membrane potential is more negative than the resting potential.
a) Refractory
b) Resting
c) Depolarization
d) Hyperpolarization
Hyperpolarization
Voltage-gated sodium channels are responsible for the __________ phase of the action potential.
a) Depolarization
b) Repolarization
c) Hyperpolarization
d) Resting
Depolarization
Voltage-gated calcium channels play a crucial role in __________.
a) Muscle contraction
b) Neurotransmitter release
c) Resting membrane potential
d) Sodium-potassium pump activity
Neurotransmitter release
Voltage-gated potassium channels are responsible for the __________ phase of the action potential.
a) Depolarization
b) Repolarization
c) Hyperpolarization
d) Resting
Repolarization
Voltage-gated calcium channels are found in high concentrations in __________.
a) Muscle cells
b) Neurons
c) Both muscle cells and neurons
d) None of the above
Both muscle cells and neurons
Voltage-gated ion channels are membrane proteins that open or close in response to changes in membrane potential. True or false?
True
Voltage-gated sodium channels have two important gates called the __________ and __________ gates.
a) Activation; inactivation
b) Opening; closing
c) Resting; active
d) Hyperpolarization; depolarization
Activation; inactivation
The opening of voltage-gated potassium channels during an action potential allows for the efflux of __________ ions.
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)
Potassium (K+)
L-type calcium channels are found in __________.
a) Skeletal muscle
b) Cardiac muscle
c) Smooth muscle
d) All of the above
All of the above
T-type calcium channels are often found in __________.
a) Neurons
b) Skeletal muscle
c) Cardiac muscle
d) Smooth muscle
Neurons
Voltage-gated calcium channels are primarily responsible for the generation of action potentials in neurons. True or false?
False
The opening of voltage-gated calcium channels triggers the release of __________ from intracellular stores in various cell types.
a) Neurotransmitters
b) Sodium ions
c) Potassium ions
d) Chloride ions
Neurotransmitters
Monosaccharides are the __________ units of carbohydrates.
a) Smallest functional
b) Largest functional
c) Building
d) Breakdown
Building
The most common monosaccharide is __________.
a) Glucose
b) Fructose
c) Galactose
d) Ribose
Glucose
Monosaccharides are classified based on the number of carbon atoms they contain, with the most common forms being __________ carbon sugars.
a) 2
b) 3
c) 4
d) 6
6
The chemical formula of glucose is __________.
a) C6H12O5
b) C6H10O6
c) C6H12O6
d) C5H10O5
C6H12O6
Monosaccharides are classified as aldoses or ketoses based on the position of the carbonyl group. True or false?
True
Aldoses are monosaccharides that have the carbonyl group on the __________ carbon.
a) First
b) Second
c) Third
d) Fourth
First
Ketoses are monosaccharides that have the carbonyl group on the __________ carbon.
a) First
b) Second
c) Third
d) Fourth
Second
Monosaccharides can exist in either a linear form or a __________ form.
a) Cyclic
b) Branching
c) Isomeric
d) Polymeric
Cyclic
The cyclic form of monosaccharides is stabilized by the formation of a __________ bond.
a) Glycosidic
b) Peptide
c) Ester
d) Hemiacetal
Hemiacetal
Monosaccharides can rotate plane-polarized light and are classified as optically active compounds. True or false?
True
Monosaccharides with an asymmetric carbon atom can exist in two mirror-image forms known as __________.
a) Enantiomers
b) Isomers
c) Diastereomers
d) Epimers
Enantiomers
Glucose and galactose are __________ of each other.
a) Enantiomers
b) Isomers
c) Diastereomers
d) Epimers
Epimers
Monosaccharides can undergo oxidation-reduction reactions, with aldehydes being oxidized to carboxylic acids. True or false?
True
Monosaccharides can undergo __________ reactions to form glycosidic bonds and produce disaccharides and polysaccharides.
a) Dehydration
b) Hydrolysis
c) Oxidation
d) Reduction
Dehydration
The primary function of monosaccharides in the body is to provide __________.
a) Energy
b) Structural support
c) Enzymatic activity
d) Cell signaling
Energy
Monosaccharides are an essential source of energy for __________.
a) Brain cells
b) Liver cells
c) Muscle cells
d) All cells in the body
All cells in the body
The breakdown of glucose in cells occurs through a process called __________.
a) Glycolysis
b) Gluconeogenesis
c) Glycogenesis
d) Glycogenolysis
Glycolysis
Monosaccharides can be converted into other biomolecules, such as amino acids and fatty acids. True or false?
True
Fructose is primarily metabolized in the __________.
a) Liver
b) Kidneys
c) Muscle cells
d) Brain cells
Liver
The conversion of glucose to glycogen is known as __________.
a) Glycogenolysis
b) Glycolysis
c) Gluconeogenesis
d) Glycogenesis
Glycogenesis
Oligosaccharides are composed of __________ monosaccharide units.
a) Two
b) Three
c) Four
d) Five
Two
Oligosaccharides are often found attached to proteins and lipids, forming __________.
a) Glycoproteins
b) Glycolipids
c) Proteoglycans
d) Polysaccharides
Glycoproteins
Oligosaccharides play a role in cell-cell recognition and cell signaling. True or false?
True
The enzyme responsible for attaching oligosaccharides to proteins during glycoprotein synthesis is called __________.
a) Glycosyltransferase
b) Glycogen synthase
c) Glycosidase
d) Glycolysis
Glycosyltransferase
The most common type of glycoprotein is __________, which has an oligosaccharide chain attached to an asparagine residue.
a) N-linked glycoprotein
b) O-linked glycoprotein
c) C-linked glycoprotein
d) S-linked glycoprotein
N-linked glycoprotein
Polysaccharides are composed of __________ monosaccharide units.
a) Two
b) Three
c) Four
d) Many
Many
Polysaccharides serve as long-term energy storage molecules in plants and animals. True or false?
True
The main polysaccharide in plant cells, used for energy storage, is __________.
a) Starch
b) Glycogen
c) Cellulose
d) Chitin
Starch
Starch is composed of two types of glucose polymers known as __________ and __________.
a) Amylose; amylopectin
b) Cellulose; chitin
c) Glycogen; chitin
d) Cellulose; amylose
Amylose; amylopectin
Cellulose is an important component of the plant cell wall and cannot be digested by humans. True or false?
True
Heparin is a type of __________ that prevents blood clotting.
a) Oligosaccharide
b) Polysaccharide
c) Glycoprotein
d) Proteoglycan
Polysaccharide
Heparin acts as an anticoagulant by inhibiting the activity of __________.
a) Clotting factors
b) Platelets
c) Red blood cells
d) White blood cells
Clotting factors
Heparin is derived from animal tissues, particularly the liver and lungs. True or false?
True
Glycoproteins are proteins that have __________ attached to them.
a) Fatty acids
b) Nucleotides
c) Sugars
d) Amino acids
Sugars
Glycoproteins are involved in various biological functions, such as __________.
a) Cell adhesion
b) Enzymatic activity
c) Immune response
d) All of the above
All of the above
The carbohydrate portion of glycoproteins is attached to the protein through a __________ bond.
a) Peptide
b) Glycosidic
c) Disulfide
d) Ester
Glycosidic
__________ is a glycoprotein hormone secreted by the placenta during pregnancy.
a) Insulin
b) Estrogen
c) Progesterone
d) Human chorionic gonadotropin (hCG)
Human chorionic gonadotropin (hCG)
Glycoproteins can serve as receptors on cell surfaces, allowing for the recognition and binding of specific molecules. True or false?
True
__________ is an example of a glycoprotein found in connective tissues, providing structural support and elasticity.
a) Collagen
b) Hemoglobin
c) Myoglobin
d) Insulin
Collagen
_____________ makes up the extracellular matrix of cartilage and tendons.
Hyaluronic acid
Proteins are composed of __________.
a) Nucleotides
b) Fatty acids
c) Amino acids
d) Monosaccharides
Amino acids
Amino acids are the building blocks of proteins. True or false?
True
The basic structure of an amino acid consists of a central __________ atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a side chain.
a) Carbon
b) Oxygen
c) Nitrogen
d) Hydrogen
Carbon
Amino acids are classified into __________ categories based on the properties of their side chains.
a) Two
b) Three
c) Four
d) Five
Three
The primary structure of a protein refers to the __________.
a) Order and sequence of amino acids
b) Folding and twisting of the protein chain
c) Interactions between multiple protein chains
d) Post-translational modifications of the protein
Order and sequence of amino acids
The side chain (R-group) of an amino acid determines its __________.
a) Size
b) Charge
c) Hydrophobicity
d) All of the above
All of the above
There are 20 standard amino acids commonly found in proteins. True or false?
True
Nonpolar amino acids have __________ side chains.
a) Hydrophilic
b) Hydrophobic
c) Charged
d) Aromatic
Hydrophobic
The bond formed between two amino acids during protein synthesis is called a __________ bond.
a) Peptide
b) Glycosidic
c) Disulfide
d) Ester
Peptide
The secondary structure of a protein refers to __________.
a) The overall three-dimensional shape of the protein
b) The sequence of amino acids in the protein chain
c) The localized folding patterns, such as alpha helices and beta sheets
d) The interactions between multiple protein chains
The localized folding patterns, such as alpha helices and beta sheets
The secondary structure of a protein is stabilized by hydrogen bonds between amino acid residues. True or false?
True
Tertiary structure refers to __________.
a) The overall three-dimensional shape of the protein
b) The sequence of amino acids in the protein chain
c) The localized folding patterns, such as alpha helices and beta sheets
d) The interactions between multiple protein chains
The overall three-dimensional shape of the protein
The quaternary structure of a protein refers to __________.
a) The overall three-dimensional shape of the protein
b) The sequence of amino acids in the protein chain
c) The localized folding patterns, such as alpha helices and beta sheets
d) The interactions between multiple protein chains
The interactions between multiple protein chains
Denaturation is a process in which a protein loses its native structure and biological activity. True or false?
True
The process of denaturation can be caused by __________.
a) Heat
b) pH changes
c) Chemicals
d) All of the above
All of the above
__________ is an example of a fibrous protein that provides structural support to tissues such as skin, hair, and nails.
a) Collagen
b) Hemoglobin
c) Myoglobin
d) Insulin
Collagen
Amino acids can be classified as essential or nonessential based on whether they can be synthesized by the body or must be obtained from the diet. True or false?
True
Essential amino acids are those that __________.
a) Must be obtained from the diet
b) Can be synthesized by the body
c) Are only found in plant sources
d) Are only found in animal sources
Must be obtained from the diet
Amino acids are joined together by peptide bonds formed through a process called __________.
Peptide synthesis or protein synthesis
__________ is an example of a conditionally essential amino acid that may need to be obtained from the diet under certain conditions, such as during illness or stress.
a) Proline
b) Tryptophan
c) Arginine
d) Tyrosine
Arginine
Peptide bonds are formed between __________.
a) Amino acids
b) Nucleotides
c) Fatty acids
d) Monosaccharides
Amino acids
A dipeptide is formed by the __________.
a) Bonding of two amino acids
b) Bonding of three amino acids
c) Bonding of four amino acids
d) Bonding of five amino acids
Bonding of two amino acids
The primary structure of a peptide refers to __________.
a) The overall three-dimensional shape of the peptide
b) The sequence of amino acids in the peptide chain
c) The interactions between multiple peptide chains
d) The secondary folding patterns of the peptide
The sequence of amino acids in the peptide chain
Peptides can exhibit specific biological activities and functions. True or false?
True
__________ is an example of a peptide hormone involved in regulating blood sugar levels.
a) Insulin
b) Glucagon
c) Thyroid hormone
d) Growth hormone
Insulin
Peptides with fewer than 10 amino acids are typically referred to as __________.
a) Oligopeptides
b) Polypeptides
c) Proteins
d) Glycoproteins
Oligopeptides
The process of breaking down peptides into individual amino acids is called __________.
a) Peptide synthesis
b) Protein denaturation
c) Peptide hydrolysis
d) Protein synthesis
Peptide hydrolysis
Peptide hormones are typically synthesized as larger precursor molecules that are then cleaved to generate the active peptide hormone. True or false?
True
__________ is a proteolytic enzyme that cleaves peptide bonds during protein digestion in the stomach.
a) Trypsin
b) Pepsin
c) Chymotrypsin
d) Pancreatic elastase
Pepsin
Peptides can have various functions, such as __________.
a) Signaling molecules
b) Enzymes
c) Structural components
d) All of the above
All of the above
Peptides are generally more stable than proteins and have longer half-lives in the body. True or false?
False
__________ is an example of a cyclic peptide with antibiotic properties.
a) Insulin
b) Oxytocin
c) Penicillin
d) Glucagon
Penicillin
Peptide bonds are formed through a condensation reaction between the __________ group of one amino acid and the __________ group of another amino acid.
a) Carboxyl; amino
b) Amino; carboxyl
c) Hydroxyl; carboxyl
d) Carboxyl; hydroxyl
Carboxyl; amino
Peptides can act as ligands that bind to specific receptors on cell surfaces. True or false?
True
The __________ structure of a peptide refers to the localized folding patterns, such as alpha helices and beta sheets.
a) Primary
b) Secondary
c) Tertiary
d) Quaternary
Secondary
Peptides are synthesized by __________.
a) Ribosomes
b) Golgi apparatus
c) Endoplasmic reticulum
d) Lysosomes
Ribosomes
Peptides are commonly used in pharmaceutical research and drug development. True or false?
True
Complete the sentence: Peptide bonds are characterized by the __________ of the carbonyl carbon and the __________ of the amino nitrogen.
Double bond character; partial positive charge
__________ is an example of a peptide that plays a role in neurotransmission and is associated with mood regulation.
a) Serotonin
b) Dopamine
c) Epinephrine
d) Acetylcholine
Serotonin
____________ is a tripeptide, occurs in erythrocytes as well as in many tissues.
a) Glutathione
b) Collagen
c) Elastin
d) Albumin
Glutathione
Fatty acids are a type of __________.
a) Carbohydrate
b) Protein
c) Lipid
d) Nucleic acid
Lipid
Fatty acids are hydrophobic in nature. True or false?
True
Fatty acids consist of a __________ group attached to a hydrocarbon chain.
a) Carboxyl
b) Hydroxyl
c) Amino
d) Phosphate
Carboxyl
The most common length of fatty acid chains in biological systems is __________ carbons.
a) 10
b) 12
c) 16
d) 20
16
Fatty acids can be classified as __________ based on the presence or absence of double bonds in their hydrocarbon chain.
a) Saturated or unsaturated
b) Monounsaturated or polyunsaturated
c) Trans or cis
d) All of the above
All of the above
Saturated fatty acids contain one or more double bonds in their hydrocarbon chain. True or false?
False
The process of adding hydrogen to unsaturated fatty acids to convert them into saturated fatty acids is called __________.
a) Dehydrogenation
b) Hydrogenation
c) Oxidation
d) Isomerization
Hydrogenation
Unsaturated fatty acids can have __________ configuration around the double bonds.
a) Cis
b) Trans
c) Both cis and trans
d) Neither cis nor trans
Cis
Omega-3 and omega-6 fatty acids are examples of essential fatty acids that cannot be synthesized by the body and must be obtained from the diet. True or false?
True
__________ is the process by which fatty acids are linked to a glycerol backbone to form triglycerides.
a) Dehydration synthesis
b) Hydrolysis
c) Lipolysis
d) Esterification
Esterification
Fatty acids can be synthesized de novo in the body through a process called __________.
a) Lipolysis
b) Lipogenesis
c) Lipid peroxidation
d) Lipoprotein lipase
Lipogenesis
Acetyl-CoA is the primary building block for fatty acid synthesis. True or false?
True
The key enzyme involved in fatty acid synthesis is __________.
a) Fatty acid synthase
b) Acetyl-CoA carboxylase
c) Hormone-sensitive lipase
d) Lipoprotein lipase
Fatty acid synthase
Fatty acids are synthesized in the __________.
a) Cytoplasm
b) Mitochondria
c) Endoplasmic reticulum
d) Golgi apparatus
Endoplasmic reticulum
Fatty acid synthesis requires ATP and reducing power in the form of NADPH. True or false?
True
The elongation of fatty acid chains during synthesis occurs through the repeated addition of __________ units.
Two-carbon (acetyl)
Fatty acids can be further modified through processes such as __________.
a) Desaturation
b) Elongation
c) Chain branching
d) All of the above
All of the above
Fatty acids are important sources of energy in the body and can be oxidized in the mitochondria. True or false?
True
__________ is an example of a long-chain omega-3 fatty acid known for its health benefits.
a) Linoleic acid
b) Palmitic acid
c) Docosahexaenoic acid (DHA)
d) Stearic acid
Docosahexaenoic acid (DHA)
Fatty acids play critical roles in the body, including __________.
a) Energy storage
b) Cell membrane structure
c) Signaling molecules
d) All of the above
All of the above
Steroids are a class of lipids characterized by a __________ core structure.
a) Carbohydrate
b) Amino acid
c) Nucleotide
d) Four-ringed
Four-ringed
Steroids are hydrophilic molecules. True or false?
False
Cholesterol is a type of __________ found in animal cell membranes.
a) Fatty acid
b) Steroid
c) Amino acid
d) Nucleotide
Steroid
The liver is the primary site of cholesterol __________ in the body.
a) Synthesis
b) Absorption
c) Metabolism
d) Excretion
Synthesis
Cholesterol is an essential molecule required for the proper functioning of the body. True or false?
True
Cholesterol is a precursor for the synthesis of various __________.
a) Proteins
b) Carbohydrates
c) Hormones
d) Enzymes
Hormones
Bile acids are synthesized from cholesterol in the __________.
Liver
Bile acids aid in the digestion and absorption of dietary fats. True or false?
True
Eicosanoids are a class of __________ derived from fatty acids.
a) Steroids
b) Proteins
c) Nucleotides
d) Signaling molecules
signaling molecules
__________ is a well-known eicosanoid that acts as a potent inflammatory mediator.
a) Prostaglandin E2
b) Estrogen
c) Testosterone
d) Cortisol
Prostaglandin E2
Eicosanoids are involved in various physiological processes, including inflammation, blood clotting, and regulation of blood pressure. True or false?
True
Cholesterol can be obtained from the diet through the consumption of __________.
a) Fruits
b) Vegetables
c) Animal products
d) Legumes
Animal products
The transport of cholesterol in the bloodstream is primarily mediated by __________.
a) Low-density lipoprotein (LDL)
b) High-density lipoprotein (HDL)
c) Very low-density lipoprotein (VLDL)
d) Chylomicrons
Low-density lipoprotein (LDL)
High levels of LDL cholesterol are associated with an increased risk of cardiovascular diseases. True or false?
True
Statin drugs are commonly used to lower cholesterol levels by inhibiting the enzyme __________ involved in cholesterol synthesis.
HMG-CoA reductase
Bile acids aid in the emulsification and absorption of __________ in the small intestine.
a) Proteins
b) Carbohydrates
c) Nucleotides
d) Fats
Fats
Bile acids are recycled in the body through a process called enterohepatic circulation. True or false?
True
Eicosanoids are derived from __________ fatty acids, such as arachidonic acid.
a) Saturated
b) Monounsaturated
c) Polyunsaturated
d) Trans fatty acids
Polyunsaturated
__________ is an example of a nonsteroidal anti-inflammatory drug (NSAID) that inhibits the synthesis of prostaglandins.
a) Ibuprofen
b) Insulin
c) Serotonin
d) Thyroxine
Ibuprofen
Cholesterol is exclusively obtained from dietary sources and is not synthesized by the body. True or false?
False
