560B Biochemistry Flashcards
The type of reaction that occurs when energy is (absorbed) from our surroundings in the form of heat.
A. Endothermic
B. Exothermic
Endothermic
Type of reaction where energy is (released) from the system and into surroundings.
Exothermic
When two similar or dissimilar types of chemical species react together with a common intermediate with the help of a metal catalyst to get a new product.
Coupling Reaction
A nucleotide made from an adenosine molecule attached to three other phosphate groups via phosphoanhydride bonds. It contains has three main parts in its complete composition: adenine, sugar, and triphosphate and is the main currency for energy.
ATP
Glycolysis takes place in the cytoplasm. True/False
True
Kreb Cycle occurs in the mitochondria. True/False
True
The electron transport chain occurs in the
A. Cytoplasm
B. Mitochondria
B Mitochondria
Which pathway generates the most ATP?
Oxidative Phosphorylation (Electron Transport Chain/Chemiosmosis)
Where is glucose 6 phosphatase found?
ER (endoplasmic reticulum)
3 key enzymes of glycolysis
Glucokinase/Hexokinase
Phosphofructokinase (PFK)
Pyruvate Kinase
4 Key enzymes of gluconeogenesis
Pyruvate carboxylase
Phosphoenolpyruvate Carboxykinase (PEPCK)
Fructose 1,6 Bisphosphatase
Glucose 6 Phosphatase
How many ATP are made in the Kreb Cycle?
2 ATP
The electron transport chain occurs in the:
mitochondria
How does glucose 6 phosphatase regulate blood sugar levels?
D -glucose 6-phosphate + H 2 O = D -glucose + phosphate Glucose is exported from the cell via glucose transporter membrane proteins. This catalysis completes the final step in gluconeogenesis and therefore plays a key role in the homeostatic regulation of blood glucose levels
FAD enters ETC (electron transport chain) at which complex?
complex 2
NADH enters ETC at what complex?
complex 1
Coenzyme Q10 is connected to which complexes in the ETC?
1, 2, 3
what is Oxidative Phosphorylation ?
The metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing chemical energy in order to produce adenosine triphosphate (ATP). In eukaryotes, this takes place inside mitochondria.
How many Protein complexes in the ETC?
There are four protein complexes that are part of the electron transport chain that functions to pass electrons down the chain. A fifth protein complex serves to transport hydrogen ions back into the matrix. These complexes are embedded within the inner mitochondrial membrane.
What are the 2 end products of oxidative phosphorylation?
ATP & Water
How many ATP are made during oxidative phosphorylation?
32-34 ATP
Explain the generation of free radicals
When cells use oxygen to generate energy, free radicals are created as a consequence of ATP (adenosine triphosphate) production by the mitochondria. These by-products are generally reactive oxygen species (ROS) as well as reactive nitrogen species (RNS) that result from the cellular redox process.
Describe the role of oxygen in oxidative phosphorylation
Oxidative phosphorylation uses these molecules and O 2 to produce ATP, which is used throughout the cell whenever energy is needed. During oxidative phosphorylation, electrons are transferred from the electron donors to a series of electron acceptors in a series of redox reactions ending in oxygen, whose reaction releases half of the total energy.
Explain Fructose and Galactose pathways
Even though glucose, galactose and fructose are metabo- lized through different pathways (Fig. 2), they all serve as substrates for glycogen synthesis and all regulate the activity of liver glycogen synthase. That is, not only are these monosaccharides substrates for glycogen synthesis, but they also regulate their own disposition in the liver, a very elegant system. Because of the regulatory activity of these monosaccharides, we developed an interest in the regulation of the glucose, fructose and galactose concentrations in the circulation, and thus in the liver cell.
Describe the PPP (pentose phosphate pathway)
PPP is a metabolic pathway parallel to glycolysis.[1] It generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides.[2] While the pentose phosphate pathway does involve oxidation of glucose, its primary role is anabolic rather than catabolic. The pathway is especially important in red blood cells (erythrocytes).
What is glucagon?
a natural substance that raises blood sugar by causing the body to release sugar stored in the liver.
Liver’s role in energy homeostasis?
Glucose homeostasis is tightly regulated to meet the energy requirements of the vital organs and maintain an individual’s health. The liver has a major role in the control of glucose homeostasis by controlling various pathways of glucose metabolism, including glycogenesis, glycogenolysis, glycolysis and gluconeogenesis.
What are ketone bodies?
Ketone bodies are produced from fatty acids, released by adipose tissue, and from ketogenic amino acids. (fasted state)
The catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA
Beta oxidation
Where does beta oxidation occur?
mitochondria
Describe triaclycerol synthesis and hydrolysis into free glycerol and fatty acids
Hydrolysis of Triacylglyerols Energy production from triacylglycerols starts with their hydrolysis into free fatty acids and glycerol. In adipose (fat‐storing) tissue, this hydrolysis is carried out by a cellular lipase, which catalyzes the hydrolysis reaction to release the free fatty acids and glycerol.
The creation of fatty acids from acetyl-CoA and NADPH through the action of enzymes is called:
fatty acid synthases.
Differentiate between odd and even chain fatty acid breakdown
Fatty acids with an odd number of carbons are a minor species and are oxidized in the same way as fatty acids with an even number of carbons. The difference is that when the odd-numbered fatty acid is oxidized, it produces propionyl CoA and acetyl CoA in the final round of degradation rather than two molecules of acetyl CoA.
A chemical reaction that transfers an amino group to a ketoacid to form new amino acids. This pathway is responsible for the deamination of most amino acids. This is one of the major degradation pathways which convert essential amino acids to non-essential amino acids (amino acids that can be synthesized de novo by the organism).
Transamination
Galactose is not as effective as glucose, so must shift to glucose 1 phosphate before entering glycolysis. True or false.
True (and the process costs 1 ATP)
What transporter does fructose use for absorption?
GLUT 5 transporter
Fed state pathways:
glycolysis, kreb cycle or glucose stored as glycogen.
Fasting state pathways:
glucagon levels rise as plasma insulin declines. liberation of fatty acids/TG
