L20: Intro to Metabolism

Question 1

What are nutrients?

Answer 1

• Substances from the environment that organisms need for cellular functions, growth, and development

Question 2

Nutrients are sources of…

Answer 2

• Major bioelements (C, H, N, O, P, S)
• Minor bioelements (i.e. Fe, Ca, Mg, Zn, Cu, etc.)
• Vitamins (i.e. riboflavin, niacin)
• Electrons
• Components involved in energy-harnessing reactions (i.e. terminal electron acceptors)

Question 3

What are bioelements?

Answer 3

• Elements found in cells and that are required for cellular function

Question 4

What is an organic molecule?

Answer 4

• Anything with C-H Bonds

Question 5

What basis are organisms grouped on?

Answer 5

• On the basis of their sources of energy, electrons and carbon

Question 6

What are the energy sources?

Answer 6

• Sunlight = “photo”

- Chemicals = “chemo”

Question 7

What are the electron sources?

Answer 7

• Organic = “organo”

- Inorganic = “litho”

Question 8

What are the carbon sources?

Answer 8

• CO2 = “auto”

- Organic compounds = “Hetero”

Question 9

What is an autotroph?

Answer 9

• “Self feeders”

- Organisms that can convert CO2 into organic carbon

Question 10

What is a heterotroph?

Answer 10

• “Other feeders”

- Organisms that get organic carbon from other organic compounds.

Question 11

Energy source, electrons, and carbon of Photolithoautotrophs.

Answer 11

• Sunlight
• Inorganic
• CO2

Question 12

Energy source, electrons and carbon of Chemolithouheterotrophs

Answer 12

• Chemicals
• Inorganic
• Organic compounds

Question 13

Where do Chemoorganoheterotrophs typically obtain their carbon from?

Answer 13

• Organic compounds. (i.e. glucose)

Question 14

What is metabolism?

Answer 14

• The set of biochemical reactions that transform biomolecules and transfers energy

Question 15

What are the 2 main types of metabolism processes?

Answer 15

• Catabolism

- Anabolism

Question 16

What is the Gibbs free energy equation?

Answer 16

• delta G = delta H - T(delta S)

- free energy = enthalpy - temperature (entropy)

Question 17

What are exergonic reactions?

Answer 17

• Products have low free energy
• free energy of reactants > products
• i.e. catabolic reactions, ATP hydrolysis
• reaction can proceed spontaneously

Question 18

What are endergonic reactions?

Answer 18

• need an input of energy to proceed
• non-spontaneous
• products have high free energy
• free energy of reactants < products
• i.e. anabolic reactions, ATP synthesis

Question 19

What is the goal in regards to energy?

Answer 19

• The goal is to capture the energy trapped in molecules (from the environment or within the cell) to synthesize high-energy intermediates (ATP, NADH, NADPH, etc.)

Question 20

What is ATP?

Answer 20

• The currency of energy in the cell
• The chemical energy of ATP is held in the weak bonds connecting the negatively charged phosphate groups
• Breaking these bonds releases the potential energy for cellular work

Question 21

What does ATP hydrolysis provide?

Answer 21

• provides energy to reactions through energetic coupling
• can provide free energy to power an endergonic reaction (+ delta G)
• i.e. when a phosphate splits from ATP to ADP, phosphorylated protein is now “activated,” higher free energy level

Question 22

What is ATP hydrolysis?

Answer 22

• an exergonic reaction (- delta G)
• spontaneous reaction
• products have lower potential energy and higher entropy (delta S) than reactants
• ATP can donate one or more phosphate(s) to another molecule

Question 23

What does energetic coupling combine?

Answer 23

• The coupling combines an endergonic reaction with an exergonic reaction