Chapter 10-Cellular Respiration Flashcards by Ariane Greenidge

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.

How well did you know this?

Not at all

Perfectly

What are the three steps or cellular respiration

glycolysis, citric acid cycle and the electron transport chain

How well did you know this?

Not at all

Perfectly

Where does glycolysis occur

In the cytoplasm of cells

How well did you know this?

Not at all

Perfectly

Is glycolysis an aerobic or anaerobic process

Aerobic

How well did you know this?

Not at all

Perfectly

Glycolysis net reaction

Glucose + 2 ADP + 2 Pi + 2NAD+ ➡️ 2 Pyruvate + 2ATP + 2NADH

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

Rate limiting enzymes in glycolysis

Phisphofructokinase 1

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

Irreversible steps in glycolysis. Pneumonic.

hexokinase, glucokinase, phosphofructokinase 1, pyruvate kinase

How- Hexokinase
Glycolysis-Glucokinase
Pushes Forward- Phosphofructokinase1
The 
Process, Kinsases- Pyruvate Kinase

How well did you know this?

Not at all

Perfectly

What are the four glucose transporters in the body?

GLUT1, GLUT2, GLUT3, GLUT4

How well did you know this?

Not at all

Perfectly

Which glucose transporters are most significant in the body?

GLUT2 and GLUT4

How well did you know this?

Not at all

Perfectly

What is the function of the GLUT2 transporter in the body?

Captures excess glucose primarily for storage

How well did you know this?

Not at all

Perfectly

Which cells contain GLUT2 transporters?

Hepatocytes and pancreatic cells

How well did you know this?

Not at all

Perfectly

What two things serve as a glucose sensor for insulin release?

The beta islet cells of the pancreas, the glycolytic enzyme: glucokinase.

How well did you know this?

Not at all

Perfectly

Where are GLUT4 transporters found in the body?

Adipose tissue and muscle tissue

How well did you know this?

Not at all

Perfectly

What is the function of GLU T4 transporters in the body?

Responses to glucose concentration in peripheral blood

How well did you know this?

Not at all

Perfectly

What is the complex of enzymes that converts pyruvate to acetyl Co-A?

Pyruvate dehydrogenase

How well did you know this?

Not at all

Perfectly

What is pyruvate dehydrogenase stimulated by? Inhibited by?

Stimulated by insulin, inhibited by acetyl CoA

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

Lengthening glycogen versus branching glycogen linkage

Lengthening glycogen uses alpha 1-4 linkages. Branching glycogen uses alpha 1-6 glycosidic linkages.

How well did you know this?

Not at all

Perfectly

Glycogen synthase

Enzyme that lengthens in glycogenesis.

Creates alpha 1-4 linkages between glucose molecules.

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

What are the two enzymes involved c glycogenolysis?

Debranching enzyme

Glycogen phosphorylase

How well did you know this?

Not at all

Perfectly

In the liver what activates the glycogen phosphorylase enzyme in glycogenolysis?

Glucagon, prevents low blood sugar.

How well did you know this?

Not at all

Perfectly

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