Chapter 10-Cellular Respiration Flashcards
Cellular Respiration
A set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules or nutrients into adenosine triphosphate (ATP), and then release waste products.
What are the three steps or cellular respiration
glycolysis, citric acid cycle and the electron transport chain
Where does glycolysis occur
In the cytoplasm of cells
Is glycolysis an aerobic or anaerobic process
Aerobic
Glycolysis net reaction
Glucose + 2 ADP + 2 Pi + 2NAD+ ➡️ 2 Pyruvate + 2ATP + 2NADH
What is the only step of glycolysis that reduces NAD to NADH?
Conversion of glyceraldehyde 3 phosphate to 1-3 bisphosphoglycerate by the enzyme glyceraldehyde 3 phosphate dehydrogenase.
Rate limiting enzymes in glycolysis
Phisphofructokinase 1
What enzyme in glycolysis uses substrate level phosphorylation?
What does this mean?
3 Phosphoglycerate Kinase
Does not require oxygen, the only means of ATP generation in an anaerobic tissue.
Irreversible steps in glycolysis. Pneumonic.
hexokinase, glucokinase, phosphofructokinase 1, pyruvate kinase 
How- Hexokinase Glycolysis-Glucokinase Pushes Forward- Phosphofructokinase1 The Process, Kinsases- Pyruvate Kinase
What are the four glucose transporters in the body?
GLUT1, GLUT2, GLUT3, GLUT4
Which glucose transporters are most significant in the body?
GLUT2 and GLUT4
What is the function of the GLUT2 transporter in the body?
Captures excess glucose primarily for storage
Which cells contain GLUT2 transporters?
Hepatocytes and pancreatic cells
What two things serve as a glucose sensor for insulin release?
The beta islet cells of the pancreas, the glycolytic enzyme: glucokinase.
Where are GLUT4 transporters found in the body?
Adipose tissue and muscle tissue
What is the function of GLU T4 transporters in the body?
Responses to glucose concentration in peripheral blood
What is the complex of enzymes that converts pyruvate to acetyl Co-A?
Pyruvate dehydrogenase
What is pyruvate dehydrogenase stimulated by? Inhibited by?
Stimulated by insulin, inhibited by acetyl CoA 
What are the two enzymes involved in glycogenesis?
Glycogen synthase: creates alpha 1-4 acidic links between glucose molecules. Activated by insulin and liver and muscle.
Branching enzyme: moves the block of oligoglucose from one chain and adds it to the growing glycogen as a new branch using Alpha 1-6 glycosidic link
Lengthening glycogen versus branching glycogen linkage
Lengthening glycogen uses alpha 1-4 linkages. Branching glycogen uses alpha 1-6 glycosidic linkages.
Glycogen synthase
Enzyme that lengthens in glycogenesis.
Creates alpha 1-4 linkages between glucose molecules.
Branching enzyme
Moves a block of oligoglucose from one chain and adds to the growing glycogen as a branch using alpha 1-6 week acidic linkage
What are the two enzymes involved c glycogenolysis?
Debranching enzyme
Glycogen phosphorylase
In the liver what activates the glycogen phosphorylase enzyme in glycogenolysis?
Glucagon, prevents low blood sugar.
In skeletal muscle what activates glycogen phosphorylase in glycogenolysis?
Epinephrine and AMP, provides glucose for the muscle itself
Products of glycogenolysis
Glycogenolysis produces significantly more glucose-1-phosphate compared to Free glucose.
What enzyme converts glucose-1-phosphate into glucose-6-phosphate
Phosphoglucomutase
What enzyme removes the phosphate from glucose six phosphate in order to make free glucose?
Glucose 6 phosphatase
Where is glucose-6-phosphatase found?
In liver cells, kidney cells (proximal convoluted tubule), colon (duodenum)
Given that muscle cells do not contain the enzyme glucose-6-phosphatase, what processes must take place in order to produce free glucose in muscle cells?
Cori cycle, alanine cycle
Where does gluconeogenesis occur?
In the cytoplasm/mitochondria of liver cells (kidneys contribute somewhat PCT)
Three steps of glycolysis and Gluconeogenesis that differ
1)Pyruvate ➡️ Oxaloacetate
Enzyme: pyruvate carboxylase
2)Fructose 1,6-bisphosphate ➡️ Fructose 6-phosphate
Enzyme:Fructose-1-6-bisphosphate
3)Glucose 6-phosphate➡️Free glucose
Where is the only place glucose 6 phosphatase found?
In the endoplasmic reticulum
Where does the PPP occur?
In the cytoplasm of most cells
What is the product of the pentose phosphate pathway?
NADPH and sugars for biosynthesis
What is the rate limiting enzyme of the pentose phosphate pathway
Glucose-6-phosphate dehydrogenase
What inhibits/activates glucose 6-phosphate dehydrogenase in the PPP?
NADPH, NADP+ and insulin
Energy from fat versus energy from carbohydrates proteins are keytones?
Fats give 9 kcal per gram of energy, carbohydrates proteins and ketones give for kilocalories per gram
The addition of a phosphate to ADP is what type of reaction?
Exergonic 
What makes ATP such a good energy carrier?
It’s high energy phosphate bonds.
Which form ATP/ADP is more stable?
ADP is more stable and thus has less energy. ATP is less stable and has more energy.
The process of breaking ATP into adenosine diphosphate ADP is called what?
ATP hydrolysis
Examples of high energy electron carriers
NADH,NADPH, FADH2, Ubiquinone, Cytochromes, Glutathione
Soluble molecules
Oxidative phosphorylation
Process by which ATP synthesis is coupled to the movement of electrons through the mitochondrial electron transport chain and the associated consumption of oxygen.
Flavoproteins
Contain a modified vitamin B (riboflavin) Nucleic acid derivatives. Involved in the modification of other B vitamins to active forms. Function as coenzymes for enzymes in the oxidation of fatty acids decarboxylation of pyruvate and reduction of glutathione.
Insulin secretion in the absorbed of or post prandial/well fed state
Insulin secretion is high anabolic metabolism prevails
Insulin and glucagon secretion in the fasting or post absorbent of states?
Insulin secretion decreases glucagon and catecholamine secretion increases
Catecholamine
Catecholamines are hormones made by your adrenal glands. Example: Epinephrine, norepinephrine, dopamine
What state is observed in short term fasting (overnight)?
Postobsorptive/fasting state. Transition to catabolic metabolism
What effect does prolonged fasting (starvation) have on glucagon and catecholamine secretion?
Dramatically increases glucagon and catecholamine secretion.
What energy source is the brains main source of energy? Are there any other forms of energy the brain can use?
The brain relies on glucose mainly for energy 2/3 of the brains energy can be derived from ketone bodies with our president when glucose is not available.
Insulin
Causes a decrease in blood glucose levels by increasing cellular uptake
What is insulins effect on the rate of anabolic metabolism
Increases the rate of anabolic metabolism
What cells of the pancreas secretes insulin?
Beta cells
Glucagon
Increases blood glucose levels by promoting gluconeogenesis and glycogenolysis in the liver
What cells of the pancreas secrete glucagon?
Alpha cells
What events stimulates glucagon secretion versus insulin secretion?
Glucagon secretion is stimulated by low blood glucose as well as high amino acid levels. Insulin is stimulated by high blood glucose levels.
What effect do catecholamines have on glycogenolysis and basal metabolic rate? Will branch of the nervous system do they work through?
Catecholamines promote glycogenolysis.
Increase basal metabolic rate.
Work through the sympathetic nervous system.
Between T3 and T4, which is more potent and which has a short half life
T3 is more potent than T4 and has a shorter half life. Available in lower concentrations.
At the tissues which thyroid hormone is converted into which?
Other tissues T4 is converted into T3
Which cells of the body are responsible for the maintenance of blood glucose levels? Through gluconeogenesis and glycogenolysis?
Hepatocytes
Adipose tissue stores and releases insulin under the influence of what hormone?
Epinephrine
Resting muscle conserve carbohydrates in what type of stores and uses what type of molecule from the bloodstream
glycogen stores, and free fatty acids in the bloodstream
Cardiac muscle uses what type of oxidation in both well fed and fasting states?
Fatty acid oxidation
In prolonged fasts the brain another nervous tissue gets its fuel from what molecules?
Ketone bodies
What hormones play a role in body mass?
Leptin: Inhibits hunger inhibits orexin Ghrelin: increases drive to eat Orexin:increases craving for food,alertness/sleep-wake cycle
Equation for BMI
Mass/Height^2
Normal BMI: 18.5-25
Overweight: 25-30
Obese: 30+
+H and +S
spontaneous/non spontaneous
Spontaneous at high temperatures
-H -S
spontaneous/nonspontaneous
Spontaneous at low temperatures
Pneumonic for the substrates of the citric acid cycle
Please can I keep selling seashells for money officer?
Pyruvate. Citrate. Isocitrate. Alpha ketoglutarate. Succinyl-CoA. Succinate. Fumarate. Malate. Oxaloacetate.
What is the net yield of ATP for one glucose molecule from glycolysis through oxidative phosphorylation?
30-32
Where does glycolysis take place?
In the cytosol
What is the Krebs cycle takes place?
In the mitochondrial matrix
What is the electron transport chain take place?
In the matrix facing surface of the inner mitochondrial membrane
In oxidative phosphorylation, each NADH and FADH2 yields how many ATP each?
Each NADH produces 2.5 ATP, FADH2 yields 1.5 ATP
Glycolysis generates what products?
2 pyruvate molecules, 2 NADH, 2 ATP (Net 4)
The transition phase between glycolysis and the Krebs cycle yields what products?
Pyruvate dehydrogenase generates a net of two NADH. One NADH per molecule of pyruvate. 2CO2, 2CoA
The citric acid cycle generates what products?
3 NADH, 1 FADH2, 1 GTP per CoA molecule
Total: 6NADH, 2FADH2, 2GTP (GTP to ATP), 4CO2
Which complexes in the electron transport chain have proton channels?
Complex 1, complex 3, complex 4
Which enzyme in the crib cycle is also a complex in the electron transport chain?
Succinate dehydrogenase which converts succinate to fumarate is also complex 2 in the electron transport chain
What enzyme is the main enzyme that assists in transitioning pyruvate to acetyl CoA?
Pyruvate dehydrogenase converts 2 pyruvate molecules into 2 acetyl CoA molecules that can then enter the krebs cycle
