Chapter 17 Energy for Biological Processes Flashcards
Metabolic activities (3) *define
(1) active transport
- nitrates (root hair cells)
- loading sucrose into sieve tube elements
(2) anabolic reactions
- building of polymers (proteins/ polysaccharides/ nucleic acid)
(3) movement
- cilia/ flagella/ contractile filaments in muscle cells
*Metabolic activities require energy.
What does radiation from the Sun do??
Radiation from the Sun… is used to fuel the metabolic reactions and processes necessary to keep organisms alive.
- before being transferred back to the atmosphere as heat
What is RESPIRATION?
The process by which organic molecules (glucose) are broken down into smaller, inorganic molecules (CO2 + H2O).
The energy stored within the bonds of the organic molecules is used to synthesise ATP.
C6H12O6 + 6O2 —> 6CO2 + 6H2O
What is PHOTOSYNTHESIS?
6CO2 + 6H2O —> C6H12O6 + 6O2
EXO OR ENDOthermic??
Photosynthesis is ENDOthermic.
- traps (takes in) energy from surroundings
Respiration is EXOthermic.
- releases energy
What is the process of CHEMIOSMOSIS?
CHEMIOSMOSIS involves the diffusion of protons from high to low concentration, through a partially permeable membrane.
How is CHEMIOSMOSIS relevant to respiration and photosynthesis.
The movement of protons down their concentration gradient RELEASES energy, which…
ADP + Pi (inorganic phosphate) —> ATP
- the attachment of Pi to ADP, forming ATP
What does CHEMIOSMOSIS depend on?
The creation of a proton concentration gradient. The energy to do this comes from high energy (excited) electrons.
How are electrons raised to higher energy levels (excited)??
- electrons present in pigment molecules (chlorophyll) are excited by ABSORBING light from the sun.
- high energy electrons are released when chemical bonds are broken in respiratory substrate molecules (glucose).
The excited electrons pass into an electron transport chain and they are used to generate a proton gradient.
What is an electron transport chain made up of?
A series of electron carriers, each with progressively lower energy levels.
As high energy electrons move from one carrier in the chain to another, energy is released.
- this is used to pump PROTONS across a membrane, creating a concentration difference across the membrane and therefore, a proton gradient.
How can protons move back through the membrane down their concentration gradient?
Through HYDROPHILIC MEMBRANE channels linked to the enzyme ATP synthase (catalyses the formation of ATP).
The flow of protons through these channels provide the energy used to synthesis ATP (from ADP and Pi).
What is the purpose of ATP in photosynthesis (1) and respiration (2)?
(1) ATP is used to synthesise glucose and other organic molecules.
(2) The ATP produced provides the energy needed for metabolic processes and reactions essential to life.
Definition of AUTOTROPHIC?
Organisms that can photosynthesise (plants and algae).
Definition of HETEROTROPHIC?
Organisms that obtain complex organic molecules by consuming OTHER heterotrophic and/or autotrophic organisms.
What do BOTH autotrophic and heterotrophic organisms do during the process of respiration?
They break down complex organic molecules, to release the energy needed to drive metabolic processes.
