Module 2 Flashcards
Define metabolism
The term used to describe all of the chemical reactions inside a cell
Compare the terms catabolic and anabolic in the context of metabolism
The term anabolism refers to those endergonic (require energy) metabolic pathways involved in biosynthesis, converting simple molecular building blocks into more complex molecules, and fueled by the use of cellular energy.
The terms catabolism refers to exergonic (release energy) pathways that break down complex molecules into simpler ones.
Catabolism - Large molecules broken down to smaller ones, releasing energy
Anabolism: small molecules are assembled into larger ones, using energy
Compare and contrast autotrophs and heterotrophs in terms of their sources of carbon source and energy source
-Autotrophs - Organisms that convert inorganic carbon dioxide into organic compounds
- Heterotrophs - Rely on more complex organic nutrients, these are provided to them initially by autotrophs.
What is an oxidation-reduction (redox) reaction?
Because electrons can move from one molecule to another, oxidation and reduction occur in tandem. These pairs of reactions are called redox reaction.
Describe why ATP, FAD, NAD+, and NADP+ are important in a cell
The energy released from the breakdown of the chemical bonds within nutrients can be stored either through the reduction of electron carries or in the bonds of ATP.
What is an electron carrier in cell metabolism
In living systems, a small class of compounds functions as mobile electron carriers, molecules that bind to and shuttle high-energy electrons between compounds in pathways.
How can electron carriers play a role in catabolism (e.g extracting energy from molecules?)
NAD+/NADH and FAD/FADH2 are extensively used in energy from sugars during catabolism in chemoheterotrophs. Whereas NADP+/NADPH plays an important role in anabolic reactions and photosynthesis.
A living cell must be able to handle the energy released during catabolism in a way that enables the cell to store energy safely and release it for use only as needed, cells accomplish this by using ATP
Briefly describe how enzymes speed up chemical reactions
Enzymes lower the activation energy by binding to the reactant molecules and holding them in such a way as to speed up the reaction
What effect do enzymes have on the activation energy of a reaction?
Enzymes lower the activation energy
Define enzyme
Proteins that serve as catalysts for biochemical reactions inside cells.
Define substrate
The chemical reactants to which an enzyme binds are called substrates
Define active site
The location within the enzyme where the substrate binds
Define enzyme-substrate complex
When an enzyme binds to its substrate it forms an enzyme-substrate complex
Define products
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Phototrophs?
Those that get their energy for electron transfer from light
Chemotrophs?
Obtain energy for electron transfer by breaking chemical bonds.