Biochem test 2 Flashcards
Proteins with nuclear export sequences (NES) are actively transported across the ore with a carrier protein using 2 GTPs. Transport in uses what? Transport out uses what?
Inportins and exportins
Where (Phase), and how much ATP is needed in Glycolysis?
The phosphorylation phase requires 2 ATP
What subunit contains the p site and the a site?
40s
How does the breakdown of amino acids help the body?
Regulation of nitrogen levels, through the excretion of excess in Urea
What type of RNA comes from the DNA, and what is the process that creates it?
mRNA and transcription
Drugs that use reverse transcriptase against itself.
Azidothymidine (AZT) or Zidovudine
What type of transport carrier protein is the sodium-potassium ATPase Pump?
Active transport carrier protein
The process that uses glycolysis and the citric acid cycle to obtain the precursors for the 20 amino acids is called?
Amino Acid Synthesis
The enzyme complex that catalyzes the final three steps of fatty acid degradation is called?
Mitochondrial trifunctional protein
This disorder causes low sugar, low ketone levels, and high ammonia when fasting or sick, because the body is trying to use fatty acids as an energy source, but can only break down those 12 carbons or less.
CPT 1 deficiency
What hormone increases when excess sugar needs storage?
Insulin
What molecule starts and ends the citric acid cycle?
Oxaloacetate
Four step process that continues fatty acid breakdown inside the mitochondria is called?
Beta-oxidation cycle
Where is cardiolipin (diphosphatidylglycerol) found?
Several locations. Especially the inner mitochondrial membrane.
A series of enzyme reactions in the liver cell mitochondria and cytoplasm to remove excess nitrogen and toxic by-product ammonia that maintains the body’s nitrogen balance is called?
The Urea Cycle
Elliptocytosis and spherocytosis are diseases that result from defects in what?
RBC membrane proteins. Specifically spectrin and ankyrin.
What enzyme starts the phosphorylation phase of glycolysis?
Hexokinase
Where does the citric acid cycle occur?
In the mitochondrial matrix
Diseases that result from misfolding of proteins are know as?
Prions
What two phases make up the metabolic pathway glycolysis?
Phosphorylation and Energy production
What does the inter conversion of a-ketogluterate, glutamate, and glutamine do for the body?
Offers an important system to utilize, generate, and/or store ammonia
Disease symptoms include low sugar, progressive destruction of peripheral nerves, breakdown of muscle, and liver/heart damage. This disease stops the conversion of lipids/fats to energy. In infancy it usually leads to death.
Mitochondrial Trifunctional protein deficiency
When there is a high concentration of NADH or FADH (products) what happens to the citric acid cycle?
It is inhibited
Where does the pentose phosphate pathway take place?
In the cytoplasm
Specialized proteins, often found near the endoplasmic reticulum, that assist in folding proteins.
Chaperones
What enzyme deficiency is involved in type 0 GSD, and where is it located?
Glycogen synthase only in the liver
In lipid metabolism, high citrate levels from the first step of CAC are a sign of excess sugar resources. What does this activate?
Acetyl-CoA carboxylase (high activity polymer)
What molecule links glycolysis to the citric acid cycle?
Pyruvate
Fatty acid synthase enzyme complex is negatively regulated by what?
Low fatty acid/fat levels in diet
Glutamate becomes glutamine via?
Transamination
The binding of different transcription factors and/or enhancers to promoter sequences are essential for positive or negative control of transcription refers to what?
Gene expression
The metabolic pathway that catabolizes hexose monosaccharides such as glucose, fructose, and galactose is called?
Glycolysis
When the body exhausts gluconeogenesis where does energy come from?
Ketone body synthesis
The removal of a COO- group is called what?
Decarboxylation
If a strand of nucleotides has Uracil what type of material is it?
mRNA
Symptoms of weakness and delayed development of muscle skills are usually evident before 1 year of age followed by blindness and death usually by age 3. Describes what disease?
Tay-Sachs disease
ATP synthase is made up of four main parts. What are they?
F0, F1, Axel/stalk, Stator
What effect both protein function and direct particular proteins to intracellular and/or extracellular destinations?
Posttranslational modifications
Phosphorylase, Glucan transferase, and Debranching enzyme are all used in what process?
Glycogenolysis
Patients with G6PDH deficiency must avoid many drugs. What are some examples?
Sulfa drugs, some anticonvulsants, thiazide and loop diuretics, some diabetic medications, some glaucoma medications, certain pain medications, and several antimalarials.
The two main anabolic pathways to produce new carbohydrate molecules are?
Gluconeogenesis, and Pentose phosphate pathway
A patient exhibiting symptoms of: glycogen accumulation in the liver, skeletal muscle and/or heart, leading to associated medical problems. Fasting low sugar. May have what type of GSD?
Type 3 GSD (Cori’s or Forbe’s)
In the energy production phase of glycolysis, how much ATP is produced?
4
The process that starts in the cytoplasm with a fatty acid linking to acyl-CoA, and ends in the inner mitochondria where the beta oxidation cycle takes place forming Acetyl-CoA is called what?
Fatty acid degradation
The primary metabolic pathways that are the main means of ATP production are?
Glycolysis, Citric acid cycle, and oxidative phosphorylation
ATP contains high energy bonds between each phosphate group. What are they called?
Phosphoric anhydride bonds
The actual yield for a glucose molecule is what?
30-32
The process where proteins are broken down into their amino acids and metabolized using carbohydrate metabolism is called?
Amino Acid Degradation
What type of reaction is occurring when NAD+ becomes NADH?
Reduction
What two molecules combine to form citrate, and begin the citric acid cycle?
Acetyl-CoA and Oxaloacetate
Disorder that occurs in three forms. Two are severe and lead to early death. It is the most common disorder of mitochondrial long-chain fatty acid oxidation.
CPT 2
Common feature of DNA promoter regions, that is an eight base-pair sequence consisting of adenine and thymine nucleotides?
TATA box
When Pyruvate reacts with pyruvate dehydrogenase what does it yield?
Acetyl-CoA
The family of enzymes that link carbohydrate molecules together are collectively known as what?
Glycosyltransferases
What has an anti-codon nucleotide sequence that hydrogen bonds with the 3 base codon of mRNA?
tRNA
When are alternative pathways for the storage of glucose promoted?
When energy levels are high
In fatty acid synthesis, the straightforward pathway on a multienzyme-protein complex in the cytoplasm is called what?
Fatty acid synthase
PPP takes place during two phases, oxidative and nonoxidative. Which phase produces products for glycolysis or nucleotide synthesis?
Nonoxidative produces Fructose-6-phosphate, and glyceraldehyde-3-phosphate. Also, converts ribulose-5-phosphate to 3-7 carbon carbohydrates that can be used for glycolysis.
Starvation and lengthy exercise that lead to low energy stores cause what metabolic pathway to occur?
Gluconeogenesis
Symptoms of: inability to perform glycogenolysis leading to muscle cramping and breakdown from exercise. Can result in kidney failure from muscle breakdown products. With an enzyme deficiency of muscle glycogen phosphorylase. Is associated with what GSD?
McArdle’s Disease (type 5)
What effect does high cholesterol content have on the cell membrane at normal and low temperatures.
Less fluid (stiffens) at normal temperature, and prevents crystallization at low temperature.
The first step of fatty acid synthesis is converting Acetyl-CoA using ATP and Acetyl-CoA carboxylase. What does this form?
Malonyl-CoA
Drugs like caspofungin, ethambutol, and others that are being developed for cancer and viral infections including HIV are effective by inhibiting or blocking bonds. Therefor these drugs are inhibitors of what?
Glycosyltransferases
The substance that alters the composition of plasma membranes and affects regulatory proteins in the lipid bilayer; resulting in beneficial changes in carbohydrate and lipid metabolism.
Virgin olive oil
Anderson’s disease (GSD type 4) exhibits symptoms of accumulation of long and unbranched glycogen molecule precipitates in the liver and heart, leading to failure and death by 1 year old. What enzyme is deficient, and how is this treated?
Glycogen branching enzyme deficiency. Treated using symptomatic treatment for liver and heart failure until a transplant is acquired.
Type 3 GSD (Cori’s or Forbe’s) is deficient in glycogen debranching enzyme. What is the treatment?
High protein diet to promote gluconeogenesis
What are the steps of Glycogen synthesis?
Glucose-6-phosphate> Glucose-1-phosphate + UTP> UDP glucose + 2 phosphates> UDP glucose then with glycogen synthase continues a branch with a 1,4 bond, or with branching enzyme produces a 1,6 bond that makes a new branch
When mRNA is being read by ribosomes it is called?
Translation
What are amino acids used for?
Proteins, nucleic acids, hormones, neurotransmitters, anti-oxidants, and signaling molecules
When glutamate dehydrogenase acts on glutamate it is called what?
the release of ammonia
Deamination
Basic gluconeogenesis pathway starts and ends with what molecules?
Pyruvate to Glucose
Sickle cell anemia, hemolytic anemia, and thalassemias are all disorders of the globin side chains of hemoglobin. They are collectively called?
Hemoglobinopathies
Glycolysis breaks down glucose into what?
2 Pyruvate, 2 ATP, 2 NADH, 2 H2O and 2 H+
The metabolic pathway that uses non carbohydrate substrates such as pyruvate, lactate, glycerol, and glucogenic amino acids to generate glucose is called? And where does it take place?
Gluconeogenesis takes place mostly in the liver and a little in the kidneys
Drugs that attack the 50s subunit in bacteria are called?
Macrolides- azithromycin, clarithromycin, erythromycin, and roxithromycin. And immunosuppressant drugs tacrolimus and sirolimus.
Synthesis of fatty acids takes place in several locations. What are they?
Liver, adipose tissue, kidney, brain, and mammary glands
The viral enzyme that copies its RNA to DNA is called?
Reverse transcriptase
Cell receptor group that does not form a channel or physically move through the membrane, instead, it transmits a signal from one side of the lipid bilayer to the other. Leads to downstream effects and turning on of secondary messengers.
Group 2 cell surface receptors
When several adenine units are added to the 3 prime end of new RNA it is called what?
Polyadenylation
What stores lipids as triacylglycerols?
Adipose tissue
What enzyme replaces hexokinase in the liver and pancreas?
Glucokinase
Medications that are used to treat heartburn, reflux, Barret’s esophagitis, and Zollinger-Ellison syndrome by blocking transport of H+. One type has the suffix -tidine, and the other -prazole.
H2 blockers and proton pump inhibitors
Name the enzymes of beta-oxidation in order.
Acyl-CoA dehydrogenase> enoyl-CoA hydratase> L-3-hydroxyacyl-CoA dehydrogenase> beta-ketothiolase
Examples of glycogenolysis inhibitors are?
Acarbose and miglitol for diabetes. Zanamivir (Relenza) and Oseltamivir (Tamiflu) for influenza
How do statins work?
Statins are competitive inhibitors of HMG-CoA reductase. (The critical and committing step of cholesterol synthesis)
What two hormones increase when energy is needed?
Epinephrine and Glucagon
Region of DNA that allows binding of RNA polymerase.
Promoter
Areas of the membrane containing high levels of cholesterol that are believed to influence membrane proteins are called?
rafts
The citric acid cycle produces what from a single pyruvate?
3 NADH, 1 FADH, 1 GTP
Where does oxidative phosphorylation exclusively take place?
Inside the inner mitochondrial membrane
The maximum amount of ATP created from one glucose molecule is what?
36
Fatty acyl-CoA of 12 carbons or less pass freely from cytoplasm through the outer and inner mitochondrial membrane, however longer fatty acyl-CoA need the assistance of what molecule and enzymes?
Carnitine and Carnitine palmitoyltransferase (CPT 1 and 2)
This antifungal medication type selectively binds to ergosterol which decreases fluidity and creates a hydrophilic channel through the membrane, leading to cell leakage and death.
Polyene antifungals
The committing step of cholesterol synthesis is what?
HMG-CoA reductase
What glycoprotein type lubricates lung and connective tissue and protects from bacterial invasion in the digestive tract? High levels in some cancers and lung diseases. Low levels may lead to ulcerative colitis.
Mucins (mucous glycoproteins)
What happens at the A site?
New amino acids bind here to be added to the peptide chain
What molecule is the predominant storage for lipids?
Triacylglycerols/triglycerides
Proteins that help in maintaining the structure and integrity of the DNA molecules.
Nuclear matrix of scaffold proteins
High levels of the molecule that represents commitment to fatty acid synthesis inhibits CPT 1. What is this molecule?
Malonyl-CoA
Patients with this disorder can develop damaged/enlarged livers (partly due to the buildup of fatty acids), kidney problems, muscle breakdown, seizures, coma, and impaired growth. What is the disorder?
CPT 1 deficiency
Medications that are used to treat high blood pressure by lowering heart rate and contraction force while increasing the diameter of blood vessels. Identified by the suffix -dipine.
Ca2+ channel blockers (CCBs)
Where does the feedback that inhibits acetyl-CoA carboxylase come from?
Palmitoyl-CoA
When there are high levels of fatty acyl-CoA what process is stimulated?
Fatty acid degradation
In glycolysis, what enzymes are regulated to allow the body to determine whether to use its carbohydrate resources for ATP production and how much to produce?
Hexokinase, phosphofructokinase-1, and pyruvate kinase
At any one time are glycolysis and gluconeogenesis functioning?
No
The step that takes advantage of the concentration gradients of products from the citric acid cycle to drive the formation of ATP is called?
Oxidative Phosphorylation
This type of protein receptor relies on conformational change resulting from the conversion of GDP to GT to convey an external signal to the inside of the cell.
G-protein receptors
Why is the theoretical yield of glucose higher than the actual?
NADH and FADH don’t yield exactly 3 and 2 ATP. It is closer to 2.5 and 1.5.
The membrane bound enzyme that catalyzes the process of moving particular phospholipid molecules from one side of the bilayer to the other when required.
Flippase
The 4 steps of pre-replication are?
- Origin recognition complex binds
2,3. Cdc6 and Cdt1 ensure the cell is ready - Minichromosome maintenance complex establishes relocation fork
Types of post translational modifications are?
Lipidation, phosphorylation, Ubiquitination, Disulfide bond, acetylation, and glycosylation
What enzyme shuts off Acetyl-CoA by phosphorylation when ATP is low?
Protein Kinase
NADPH, the primary molecule indirectly responsible for eliminating toxic oxygen radicals is produced by what?
Pentose phosphate pathway
Which is an important intermediate in the biosynthesis of unesterified fatty acids? A. Carnitine B. Cholesterol C. Fatty acyl-CoA D. Glucose E. Malonyl-CoA
E. Malonyl-CoA
Heart failure, diabetes, Alzheimer’s, and Parkinson’s all show changes of this molecules’ composition of the mitochondrial membrane. What is the molecule?
Cardiolipin
The phase of oxidative phosphorylation where NADH/FADH transfer electrons to O2, pumping H+ across the membrane, and making H2O is called?
Oxidative
Cell receptor group that the signal passes through membrane by diffusion, and binds to an intercellular target.
Group 1 intracellular receptor proteins
Fasting for a days leads to what being used for energy?
Ketone bodies
Fatty acids with an odd number of carbon atoms rely on the substitution of what molecule for production?
Propionyl-CoA
When DNA is transcribed, what direction does it read, and what is the DNA strand called?
3 to 5 and template strand
Type of antibiotics and antifungals that disrupt the correct balance of various ions inside and outside of cells by interfering with the cells maintenance of its membrane function of membrane channels. Peptide of lipid based molecules.
Ionophore
What enzyme does HIV use to turn its RNA into DNA, so it can use the cells mechanisms to replicate?
Reverse transcriptase
What is the treatment for type 0 GSD?
Diet changes to avoid low and high blood sugar levels. (Avoid processed carbohydrates)
The substance that alters the composition of plasma membranes and affects regulatory proteins in the lipid bilayer; resulting in beneficial changes in carbohydrate and lipid metabolism.
Virgin olive oil
Very-long-chain-fatty acids (VLCFA) greater than 22 carbons have to be broken down into 8 carbon octanyl-CoA that are transferred to the mitochondria. What process does this, and what molecules does it use?
Peroxisomal oxidation uses carnitine to transport VLCFA and peroxisomes to oxidize the lipid.
Where does glycolysis exclusively occur?
The cytoplasm
What enzyme links sugar and fatty acid metabolism, and is the key branch point of human metabolism and is highly controlled based on the body’s nutritional state and needs?
Acetyl-CoA
List in order the enzymes of glycolysis.
Hexokinase/glucokinase> Phosphofructokinase-1> Phosphoglycerate kinase> Pyruvate kinase
What disease type causes: detrimental and fatal neurological symptoms, dementia, problems with memory/speech/movement/balance, personality changes, hallucinations, and seizures. By creating holes in normal brain tissue.
Protein misfolding, prions
Glycolysis is activated in response to what?
Low energy stores
What are the sources of amino acids?
Body proteins degradation
Dietary Proteins
Synthesis of non-essential amino acids
Different enzymes regulate conversion of Pyruvate back to glucose, however they are at the same locations. What are they? (In order)
Pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1,6-biphoshatase, and glucose-6-phosphatase
What G class inhibits cAMP production; minor role in stimulation of phospholipase C
G-I
What molecules begin the phosphorylation phase?
Glucose and ATP
Gluconeogenesis is more energy expensive than glycolysis. What does it use?
4 ATP, 2 GTP, and 2 NADH
Acetyl-CoA is an important component of what neurotransmitter?
Acetylcholine
What maintains balance of lipids, including cholesterol?
The liver
The theoretical yield for a glucose molecule is what?
36 ATP
The nuclear matrix is a structure thought to be a 3D network of what?
Intermediate filaments
Heart failure, diabetes, Alzheimer’s, and Parkinson’s all show changes of this molecules’ composition of the mitochondrial membrane. What is the molecule?
Cardiolipin
Beta oxidation produces several acetyl-CoA units, however if there is an odd number of carbons a three carbon propionyl-CoA molecule is produced. What is it converted to and where can it be used?
Succinyl-CoA in the citric acid cycle
What G class causes cAMP production via adenyl cyclase and protein kinase A signaling (multiple targets)
G-s
Disorders that are caused by mutations that affect the proteins of the nuclear membrane or lamina. Have far reaching effects, often resulting in childhood or adolescent disorders of skeletal and cardiac muscles, lipid, skin, nerves, and white blood cells, as well as cancers, diabetes, premature aging, and even early death.
Laminopathies
What type of reaction is occurring when NADH becomes NAD+?
Oxidation
Patients with this display symptoms of RBC breakdown that results in liver and kidney problems.
Glucose-6-phosphate dehydrogenase (G6PDH) Deficiency
What is produced by every acetyl-CoA fragment from beta oxidation?
1 NADH + H+, 1 FADH
What happens at the P site?
When tRNA is here the peptide chain on the 60s unit grows
What patients will show high ketone bodies?
Untreated diabetics, those on low cholesterol/high fat diets, and someone who is fasting/starving.
Where do the two nitrogens that make up urea come from?
Glutamate and Aspartate
Fasting for 12 hours leads to what?
Glycogen breakdown
Ketone body synthesis/degradation is regulated by what?
Oxaloacetate
A patient is on the verge of starvation. What do you expect his oxaloacetate level to be?
Low with high ketone bodies
What G class stimulates phospholipase C
G-q
What molecule is produced via glycolysis and the citric acid cycle that represents a form of alternative energy storage than ATP?
NADH
Toxic nitrogen waste is largely excreted as what?
Urea
The two subunits that make up human ribosomes are?
40s and 60s
What type of glycogen storage disease exhibits symptoms of: fasting low sugar, lactate, and alanine as well as high ketones and fatty acids. During feeding high sugar and lactate. Can have muscle cramps.
GSD type 0
Tay-Sachs disease is caused by a deficiency of what enzyme?
beta-N-acetylhexosaminidase
