CHapter 1 Powerpoint, Schemes and Mind Maps of Biochemistry

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BICH 411

Metabolism

Dr Pozzi

Email: shendersonpozzi@tamu.edu

Office Hrs: Zoom

Mon 10 – 11:30 am, Wed 3 pm – 4pm

Syllabus

• All information is available in the syllabus
• Please note:
  • Recitation – discuss topics from class in previous weeks, asynchronous delivery
  • Use of Disability Services – talk with me in private, but recognize, test dates need to be set immediately, send necessary paperwork
  • Make-up work can only be done with a Univ Excused Absence and proper verification in required time set by university for exams
  • HW has no makeup opportunity, as the assignment is posted for 3-4 days minimum and submission window will open for 24 hrs and from your home. Keys will be immediately released as exam will be in coming day
  • Quizzes will have no make ups, there are seven quizzes and only the top five quiz grades will count

METABOLISM

One of the great unifying principles of modern biology is that organisms show similarity in major pathways of metabolism

Figure 17.

Metabolism

• The sum of all of the chemical reactions occurring in the cell.
• The overall processes by which living things acquire and utilize free energy in the cell.
• Living organisms need a continuous influx of energy to battle entropy.
• Metabolism requires tightly coordinated cellular activity.

Hint: How to approach

Pathways

Look at energetics of reactions: Help you determine the points of regulation for each pathway – those reactions catalyzed by enzymes unique to that pathway whose level of activity dictate whether the pathway is turned off or on

STUDY HELP!! How can I study more effectively??

Glucose

2 Pi

2(3PG)

2 NAD+ 2 NADH

2 ADP

2 ATP

2 ATP

2 Pyruvate

2 PEP

2 ADP

2(GA3P)

2 ADP 2 ATP

The Four Functions of Metabolism

• Obtain free energy for the cell.
• Degrade macromolecules as required for biological function.
• Convert nutrients into macromolecules.
• Assemble macromolecules into cellular structures.

Metabolism

• Metabolism consist of catabolism and anabolism.
• Catabolism degradative pathways.
  • Usually producing free energy!
• Anabolism biosynthetic pathways
  • Usually consuming free energy!

Figure 17.6 Anabolism and Catabolism are Interrelated

UNDERSTAND HOW THE RELATIONSHIP BETWEEN THE TWO PROCESSES (AKA ATP , NADH , AND NADPH )

Why ATP is a “high energy” compound?

Hydrolysis increased

resonance stabilization

• Figure 3b in your text

Hydrolysis  decreased

electrostatic interaction

• Charges usually shielded by Mg +

Hydrolysis  increased

energy of solvation

• More disordered system

Know complete

structure of ATP

Standard Free Energies of Phosphate Ester Hydrolysis of Some Biological Compounds

Compound ∆Go^ ’ (kJ/mol)

Phosphoenolpyruvate (PEP)

-61.

1,3- Bisphosphoglycerate

-49.

Acetyl phosphate -43.

Phosphocreatine -43.

ADPAMP + Pi -35.

PPi2 Pi -33.

ATPAMP + PPi -32.

ATPADP + Pi -30.

Glucose-1-phosphate -20.

Fructose-6-phosphate -15.

Glucose-6-phosphate -13.

Glycerol-3-phosphate -9.

AMPadenosine + Pi -9.

Know complete

structure of

NADH

& NADPH

NADH used in fuel

metabolism

NADPH used for

biosynthesis

2’ O- | -O-P=O | O- NADPH

NAD +^ Collects Electrons Released in Catabolism

ELECTRONS TRANSFERRED TO ELECTRON ACCEPTOR IN OXIDATIVE PHOSPHORYLATION TO GENERATE ATP

Figure 17.11 Hydrogen and electrons released in the course of oxidative

catabolism are transferred as hydride ions (H: -^ ) to the pyridine

nucleotide, NAD+, to form NADH + H +^ in dehydrogenase reactions.

NADPH Provides the Reducing Power for Anabolic

Processes

Figure 17.12 Transfer of reducing equivalents from catabolism to anabolism via the NADPH cycle.

NADPH Provides the Reducing Power for Anabolic Processes

• Whereas catabolism is oxidative, anabolism is reductive
• Biosynthesis typically relies on reducing equivalents from NADPH
• NADPH can be viewed as the carrier of electrons from catabolic reactions to anabolic reactions

Figure 17.6 Anabolism and Catabolism are

Interrelated

How are these the end products of degradation?

UNDERSTAND HOW THE RELATIONSHIP BETWEEN THE TWO PROCESSES (AKA ATP , NADH , AND NADPH )