The Energy of Life - Chapter 4: Lecture 1

These flashcards cover the fundamental concepts presented in the lecture regarding energy, metabolism, thermodynamics, enzyme activity, and cellular transport.

What is the definition of energy in the context of living organisms?

Energy is the ability to do work.

Where do living organisms primarily obtain energy?

From the sun.

What is photosynthesis?

Photosynthesis is the process by which plants and some microbes use CO2, water, and sunlight to produce sugars.

What are the two forms of energy discussed in the lecture?

Kinetic energy and potential energy.

What is potential energy?

Stored energy available to do work.

What do calories (cal) measure?

Calories are used to measure energy.

What does the first law of thermodynamics state?

Energy cannot be created or destroyed, only converted from one form to another.

What does the second law of thermodynamics emphasize about energy transformations?

All energy transformations are inefficient because some energy is always lost as heat.

Define entropy.

Entropy is the measure of disorder or randomness in a system.

What is metabolism?

Metabolism encompasses all chemical reactions in an organism.

What is the difference between catabolism and anabolism?

Catabolism is the process of breaking down materials, while anabolism is the process of building larger substances from smaller ones.

What are endergonic reactions?

Endergonic reactions require an input of energy and produce products that contain more energy than the reactants.

What are exergonic reactions?

Exergonic reactions release energy and produce products that contain less energy than the reactants.

What is ATP and its role in cells?

ATP is the cellular energy currency that provides energy for various cellular processes.

How do enzymes affect chemical reactions?

Enzymes speed up chemical reactions by lowering the activation energy.

What is negative feedback in metabolic pathways?

Negative feedback slows down the synthesis of a chemical product by inhibiting the enzyme that catalyzes the initial reaction.

What is osmosis?

Osmosis is the diffusion of water across a selectively permeable membrane.

What happens to a cell placed in a hypotonic solution?

Water moves into the cell, causing it to swell.

What is the primary role of membrane transport in cells?

To maintain internal equilibrium and facilitate the movement of molecules across membranes.

What affects the rate of diffusion?

Concentration gradient, mass of molecules, temperature, and solvent density.

What do cofactors do in enzymatic reactions?

Cofactors assist enzymes in catalyzing reactions and are not consumed in the process.

Name an example of a competitive inhibitor.

A molecule that attaches to the active site of an enzyme, preventing the substrate from binding.