introduction to metabolism

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Introduction to Metabolism SBI4U Biology

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Introduction to Metabolism. SBI4U Biology. What does Metabolism mean?. The overall process by which an organism obtains nutrients, deals with them, and extracts energy from them. How the organism uses that energy. - PowerPoint PPT Presentation

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Page 1: Introduction to Metabolism

Introduction to MetabolismSBI4U Biology

Page 2: Introduction to Metabolism

What does Metabolism mean?

• The overall process by which an organism obtains nutrients, deals with them, and extracts energy from them.

• How the organism uses that energy.

• The specific biochemical processes that happen at the cellular level to allow this.

• Energy Balance

Page 3: Introduction to Metabolism

Metabolism has two phases:

• ANABOLISM:• ‘building up’• forming cells,

tissues…• going from simpler

molecules to more complex ones.

• synthesis of polymers

• CATABOLISM:• ‘breaking down’• digesting nutrients,

ingesting food…• going from more

complex molecules to simpler ones

• hydrolysis of polymers

Page 4: Introduction to Metabolism

Catabolism!

• Ingestion• Digestion• Hydrolysis• You eat an

egg so that you can obtain amino acids for your own body’s use.

Page 5: Introduction to Metabolism

Anabolism!

• Growth• Repair• Polymerization• Using the

amino acids from that egg you ate to build muscle.

Page 6: Introduction to Metabolism

It’s a big give & take:

Page 7: Introduction to Metabolism

BMR: Basal Metabolic Rate

• Basal = most basic, lowest

• Genetically determined

• The metabolic cost of staying alive

• i.e., the energy for life processes such as breathing, circulation, nerve function, body heat, etc.

• Can be increased temporarily

Page 8: Introduction to Metabolism

BMR: Basal Metabolic Rate

• BMR changes with age:

Page 9: Introduction to Metabolism

Factors affecting Metabolism:

• Highest in infancy, Lowest in old age• Level of activity & Exercise• Stress• Fever• Dietary choices

Page 10: Introduction to Metabolism

Factors affecting Metabolism:

• Thyroid gland = one of our main organs regulating metabolic rate.• Hyperactive = weight loss• Hypoactive = weight gain

Page 11: Introduction to Metabolism

Balance matters:

Energy in > Energy out = weight gain

Energy out > Energy in = weight loss

Eating disorders can complicate matters.

Page 12: Introduction to Metabolism

We think this is a recent, or modern-day problem, but look at this Kellogg’s advertisement from the early 1900’s

Page 13: Introduction to Metabolism

Where do we extract the energy?

• Cell Metabolism• Mitochondrion• Different molecules are processed by different

reactions• Some cells are specialized to one or two ‘jobs’.

Page 14: Introduction to Metabolism

How is metabolism studied?

• In metabolism experiments, rats are fed radioactively tagged sugars, and their carbon dioxide output is measured.

• Glucose + Oxygen Water + Carbon Dioxide + Energy

Page 15: Introduction to Metabolism

What do you mean, ‘energy’?

• Specifically the energy is obtained as Adenosine Triposphate, or ATP.

• This is the energy currency of all living things.

• C6H12O6 + O2 H2O + CO2 + ATP

Page 16: Introduction to Metabolism

Example: What happens to Glucose

Page 17: Introduction to Metabolism

The details: three major nutrients

Page 18: Introduction to Metabolism

The Big Picture… don’t panic!