ANSC 221 Exam 2

What forms of reducing equivalents are REDUCED?

1. FADH2

2. NADH

Which cellular structures are linked together across cells by the extracellular matrix?

1. Cytoskeleton

2. Cell membrane

What are Glycoproteins?

Protein-carbohydrate macromolecule with more protein monomers than carbohydrate

What are Proteoglycans?

Protein-carbohydrate macromolecule with more carbohydrate monomers than protein

What are Integral proteins?

Protein embedded in the cell membrane

What are Peripheral proteins?

Protein associated with edge of the cell membrane

What are Transporters?

Protein that facilitates movement of molecules across the cell membrane

What is associated with the MAJOR glycoprotein in the extracellular matrix?

• Glycine

• Fibrous protein

• Collagen

• Fibroblasts

(True/False) Collagen accounts for roughly 40% of the mammalian body mass.

False

collagen accounts for 40% of all protein

What is the function of Fibronectin?

Anchors collagen to integral proteins

What is the function of Glycoproteins?

Provides structure to the extracellular matrix

What is the function of Proteoglycans?

Provides function in the extracellular matrix

What is the function of Integrin?

Anchors peripheral proteins to the cytoskeleton

What is true of TIGHT JUNCTIONS?

• Interact with microfilaments

• Water-tight

• Integral proteins

What is true of DESMOSOMES?

• Not water-tight

• Interact with intermediate filaments

• Integral proteins

(True/False) Gap junctions allow adjacent cells to share macromolecule polymers.

False

allows the sharing of small molecules

not polymers

What does Amphibolic mean?

Metabolic pathway including both degradation and synthesis

What does Anabolic mean?

Metabolic pathway in which synthesis of molecules occurs

What does Catabolic mean?

Metabolic pathway in which degradation of molecules occurs

(Mitochondrial morphology) Intermembrane space

Segmented region

holds protons pumped out of the matrix during electron transport

(Mitochondrial morphology) Mitochondrial matrix

Segmented region

fluid inside inner membrane

site of important metabolic reactions

(Mitochondrial morphology) Inner membrane

Preserves proton gradient that powers oxidative phosphorylation

functional barrier

(Mitochondrial morphology) Outer membrane

Permeable layer that allows movement of ions/molecules into and out of the organelle

(Mitochondrial morphology) Cristae

Folded regions of the inner membrane that facilitate metabolism

increase surface area and allow enzymes more opportunity to react

What are Metabolites?

Reactants

How do Enzymes affect Metabolic Pathways?

• Catalyze reactions in specific order

• Proceed until pathway is regulated OR reactants are gone

• Some enzymes catalyze reactions in both directions depending on cellular conditions *Phosphorylation increases/decreases enzyme activity *Transport proteins can be removed/pinched

What is Macromolecule Synthesis?

• Dehydration synthesis

• One monomer forms a covalent bond to another monomer (or growing chain of monomers)

What is Glycolysis?

• "Splitting sugars"

• Breakdown of glucose by enzymes -> releases energy and pyruvic acid

• Yields 2 molecules of ATP

How do Macromolecules hold energy?

• Fatty acid oxidation

• Energy can be transferred from one storage site to another

How do Reducing Equivalents (FAD and FADH2) hold energy?

• Have structures with resonance that are great at holding bonds

• Electrons will enter the Electron Transport Chain

How do Nucleotide Triphospholipids (GTP

UTP

What scenarios reflect methods by which metabolic pathways may be regulated?

1. Glycogen phosphorylase is phosphorylated

What Carbohydrate Metabolism processes are catabolic?

• Glycogenolysis

• Glycolysis

• Pyruvate oxidation

• TriCarboxylic Acid (TCA)/Citric acid cycle

• Electron Transport Chain

What Carbohydrate Metabolism processes are anabolic?

• Gluconeogenesis

• Glycogenesis (create glycogen)

What is Phosphorolysis?

Bond cleavage by the substitution of a phosphate group

(Glycogenolysis) Glycose-1-P is isomerized to:

Glucose-6-P

(Glycogenolysis) Glycogen is catabolized into:

Glucose to be metabolized

The fate of glucose derived from Glycogenolysis is:

Tissue-dependent

Glycolysis has energy:

Input and output phases

The Glycolysis energy INVESTMENT phase:

• CONSUMES ATP

• First phosphorylation traps G6P in the cell

• Can no longer utilize glucose transporters

• Second phosphorylation commits F1

The Glycolysis energy PAY-OFF phase:

• YIELDS ATP

• Specific enzymes participate in energy transfer

• Kinases

Glucose molecules can be reformed via:

Gluconeogenesis

What is Gluconeogenesis?

Synthesis of glucose from non-carbohydrate precursors (proteins

What cell types oxidize glucose for most of their energy?

1. Stem cells

2. Immune cells

3. Neurons

Macronutrient metabolism yields specific metabolites that can be returned:

To glucose via gluconeogenesis

In Gluconeogenesis

Glycerol can be derived from:

In Gluconeogenesis

Pyruvate can be derived from:

In Gluconeogenesis

Oxaloacetate can be derived from:

Pyruvate ______ follows Glycolysis

Oxidation

Glucose is catabolized to _____ by the end of Glycolysis

Pyruvate

Pyruvate is ANAEROBICALLY converted to _____ via Lactate Dehydrogenase

Lactate

Where does Lactate fermentation occur?

Cytosol

In Lactate fermentation

_____ is regenerated/oxidized

Lactate fermentation has a _____ lower energy yield and can't enter the TCA

Lower

Pyruvate is AEROBICALLY converted to ______ via Pyruvate Dehydrogenase

Acetyl CoA

Where does Aerobic respiration occur?

Mitochondria

In Aerobic respiration

more _____ is generated

Aerobic respiration has a _____ net energy yield and can enter the TCA

Higher

The TriCarboxylic Acid cycle (TCA) is the major source of _______ that enter the Electron Transport Chain

Reducing equivalents

Acetyl-CoA molecules entering TCA generates:

Multiple forms of energy capture

Acetyl-CoA molecules entering TCA generates ____ molecule(s) of NADH

3

Acetyl-CoA molecules entering TCA generates ____ molecule(s) of FADH2

1

Acetyl-CoA molecules entering TCA generates ____ molecule(s) of GTP

1

Acetyl-CoA molecules entering TCA generates what other end products?

• 2 CO2 molecules

• Oxaloacetate

Is there a true end to the TCA?

No

as long as more molecules can be produced

it is a true cycle and never ends

The TCA has how many total reactions?

8

What does Citrate Synthase do?

It catalyzes the condensation of acetyl-CoA and oxaloacetate to form citrate

What does Aconitase do?

Isomerizes citrate to isocitrate

What does Isocitrate Dehydrogenase do?

It oxidizes isocitrate to produce alpha-ketoglutarate and CO2 as NAD+ is reduced to NADH to store 2 electrons

What does Alpha-Ketoglutarate Dehydrogenase do?

It oxidizes alpha-ketoglutarate to produce succinyl-CoA and CO2 as NAD+ is reduced to NADH to store 2 electrons

What does Succinyl-CoA Synthetase do?

• The activated acyl group of succinyl-CoA is used to produce GTP which is then used to make ATP

• The end product of this reaction is succinate

What does Succinate Dehydrogenase do?

Succinate is oxidized to fumarate as FAD is reduced to FADH2

What does Malate Dehydrogenase do?

Malate is oxidized to oxaloacetate as NAD+ is reduced to NADH

_______ metabolism converge at TCA

Carbohydrate

______ can go back through the cycle and become glucose when in excess

Oxaloacetate

Glycogen is ____ and takes up ____

Super hydrophilic

Triglycerides are _____ and take up ____

Hydrophobic

Too much _____ inhibits the TCA cycle

CO2

_____ steers pathways

important in ETC

Oxygen

What is Substrate level phosphorylation?

Direct usage of E from chemical bonds to phosphorylate ADP

What is Oxidative phosphorylation?

Indirect capture of E by creation of electrochemical gradient

• Allows capture of energy in form of ATP

• Reducing equivalents require ETC to capture energy

Route taken into mitochondria determines _______

Net yield of ATP

Oxygen is the terminal ______

Electron acceptor

Electrons end up on _____ to create water

Oxygen

ETC complexes turn chemical bonds into ______

Electrochemical potential

Complexes are ____

Enzymes and transporters

What metabolic pathways are ANABOLIC?

1. Gluconeogenesis

2. Glyogenesis

(True/False) Glucose-6-Phosphate is the direct product of glycogen in glycogenolysis.

False

Glucose-6-Phosphate comes from Glucose-1-Phosphate

Which enzyme determines whether glucose liberated from glycogen enters circulation to supply other organs (as in the liver) or enters glycolysis (as in skeletal muscle)?

Glucose-6-Phosphatase

G6P is _____ to G1P

Isomerized