Energy Flow Flashcards
Metabolism
Sum of all biochemical reactions that occur within a cell
Chemical reactions
Reactions that change the molecular formula of a molecule
Activation energy
The amount of energy required for a reaction to start
Where is reaction energy usually sourced from?
Environmental heat
Reactant
Substrate, the molecule or molecules that are present at the beginning of a chemical reaction and become the product
Product
The result of a chemical reaction
Endergonic/endothermic reactions
A reaction in which heat is absorbed and a larger molecule is formed from multiple smaller ones
Dehydration synthesis, protein synthesis, DNA synthesis, RNA synthesis, and photosynthesis
Exergonic/exothermic reactions
A reaction in which heat is released and a molecule is broken down into simple compounds
Hydrolysis, cellular respiration
Enzyme
Protein biocatalysts that lower activation energy to make chemical reactions happen faster and only work with specific substrates
Generally end in -ase
Active site
The part of an enzyme that binds with the substrate
Denaturation
An enzymes shape changes and it no longer functions because the substrate no longer fits in the active site
What causes denaturation of enzymes?
pH changes, temperature changes, and salt concentration
What chemical reactions do enzymes regulate?
Making materials that cells need, releasing energy, transferring information
How do minor temperature changes affect enzymes?
Lower temperatures make enzymes slower and higher temperatures make enzymes faster
Inhibitors
Slow down enzyme activity
Competitive inhibitors
Occupy the active site and block substrates from entering
Noncompetitive inhibitors
Completely fill the active site so that there is nowhere for substrates to enter
Adenosine triphosphate
Energy carrying molecule that carries and stores energy for cell functions
In the ATP-ADP cycle what is and isn’t recycled?
ADP is recycled, phosphate is not
When is the energy from the third phosphate bond released?
Phosphorylation when it attaches to another molecule
Where is the energy in ATP stored?
The bond between the second and third phosphates
Is breaking down ATP endothermic or exothermic?
Exothermic
Is ATP being formed endothermic or exothermic?
Endothermic
Chemiosmosis
Movement of ions down a concentration gradient
What forms ATP from ADP?
ATP synthase
What is used to attach the third phosphate?
Energy from food
When is ATP formed?
Cellular respiration
How many ATP molecules can be made from a molecule of glucose?
~36
How many ATP molecules can be made from a molecule of glycerol?
~15-20
Producers
Autotrophs, get energy from nonliving sources
Consumers
Heterotrophs, get energy from living or once living sources
Photosynthesis
Uses energy from the sun
6CO2 + 6H2O= C6H12O6 + 6O2
What organisms perform photosynthesis?
Plants and cyanobacteria
Chemosynthesis
Uses energy from chemicals like sulfur and methane
6CO2 + 18H2S + 3O2 = C6H12O6 + 12H2O + 18S (sulfur version)
What organisms perform chemosynthesis?
Deep sea bacteria
What is the same in photosynthesis and chemosynthesis?
Both produce sugars and use nonliving energy sources
How do consumers get energy?
They ingest organisms and digest them to release ATP during cellular respiration
Herbivores
Eat vegetation
Carnivores
Eat meat
Omnivores
Eat meat and vegatation
Detritivores (decomposers)
Eat dead materials
Food chains
Trace energy flow and show trophic levels
Trophic levels
Levels of nourishment in a food chain
1 = producer, 4 = tertiary consumer
Food webs
Show multiple food chains and how they connect
Rule of 10
Only 10% of energy from the previous level is passed on
Where does most energy obtained go?
90% of energy is used for metabolism or released as heat
