Topic 5 - Key Terms Flashcards
What is acetyl coenzyme A?
A two carbon molecule formed during the link reaction when acetate combines with co enzyme A. It is then oxidised in the Krebs cycle.
What is adenosine triphosphate?
A universal energy molecule found in all living cells.
What is aerobic respiration?
Cellular respiration that occurs in the presence of oxygen producing carbon dioxide water and ATP. It involves four stages: glycolysis, the reaction, the crab cycle and oxidative phosphorylation.
What is ammonification?
The conversion of organic nitrogen containing compounds into ammonia by saprobiontic microorganisms resulting in ammonium ions being added to the soil.
What is an anaerobic respiration?
Cellular respiration that occurs without oxygen. In animals lactate is produced while in plants and microorganisms ethanol and carbon dioxide are formed. Less ATP is generated compared to aerobic respiration.
What are artificial fertilisers?
Man-made substances often containing nitrogen, phosphorus, and potassium, used to enrich soil.
What is ATP synthase?
An enzyme embedded in cellular membranes that synthesises ATP from ADP as protons pass through it.
What is biomass?
The total mass of organic material in a specific area over a defined time measured as dry mass or carbon content.
What is calorimetry?
A method for estimating the chemical energy content of dry biomass.
What is a carnivore?
An animal that consumes other animals for energy, functioning as secondary or tertiary consumers.
What is chemiosmotic theory?
The production of ATP driven by the movement of protons down their concentration gradient through ATP synthase.
What is chlorophyll?
A pigment in chloroplast thylakoids that absorbs light energy and becomes ionised during photosynthesis.
What are coenzymes?
Molecules that assist enzyme activity, such as NAD, FAD, and NADP.
What are consumers?
Organisms that gain energy by feeding on other organisms.
What is denitrification?
The reduction of nitrate ions into nitrogen gas by denitrifying bacteria in an anaerobic conditions like waterlogged soils.
What is denitrifying bacteria?
Microorganisms that convert nitrate ions into nitrogen gas in oxygen poor environments.
What is an ecosystem?
A system comprising living organisms and nonliving components interacting with a specific area.
What is efficiency of energy transfer?
The ratio of energy transfer between trophic levels calculated as:
Efficiency = energy transferred/total energy available x 100
What is an electronic acceptor?
Oxygen act as the final electron acceptor in the electron transport chain.
What is the electron transfer chain?
A series of proteins that transfer electrons through oxidation reduction reactions, facilitating ATP synthesis.
What is eutrophication?
The excessive enrichment of water bodies with nutrients often from fertilisers leading to environmental imbalances.
What is FAD?
A molecule that accepts protons and electrons during the Kreb’s cycle forming reduced FAD.
What is the food chain?
A representation of feeding relationships and energy transfer in a sequence.
Producer - primary consumer - secondary consumer - tertiary consumer
What is a food web?
A network of interconnected food chains within an ecosystem.
What is glycerate 3-phosphate?
A three carbon molecule reduced to triose phosphate using reduced NADP and ATP during the light independence stage of photosynthesis.
What is glycolysis?
The initial stage of respiration occurring in the cytosol breaking glucose into two pyruvate molecules producing ATP and reduced NAD.
What is gross primary production?
The total chemical energy stored in plant biomass in a specific area or volume.
What is a herbivore?
Primary consumers that feed exclusively on plants.
What is the Kreb’s cycle?
A series of reactions in the mitochondrial matrix that oxidise acetyl coenzyme A, producing reduced NAD, reduced FAD, ATP, and carbon dioxide.
What is leaching?
The loss of nutrients from soil due to rainwater.
What is the light dependent reaction?
The stage of photosynthesis where light energy produces ATP reduced NADP and oxygen in the thylakoids.
What is the light-independent reaction?
The photosynthesis stage using carbon dioxide ATP, and reduced NADP to produce sugars in the chloroplast stroma.
What is a limiting factor?
A variable that restricts the rate of a process, such as light intensity in photosynthesis.
What is the link reaction?
A step in aerobic respiration that converts pyruvate into acetyl coenzyme A, producing reduced NAD and carbon dioxide.
Pyruvate + NAD + CoA -> acetyl CoA + reduced NAD + CO2
What is mycorrhizae?
Symbiotic relationship relationships between fungi and plant roots enhancing water and nutrient absorption.
What is NAD?
A molecule that accepts protons and electrons in aerobic respiration forming reduced NAD.
What is NADP?
A molecule that except protons and electrons during the light dependent reaction forming reduce NADP.
What are natural fertilisers?
Organic materials like compost or manure used to improve soil nutrient content.
What is the net primary productivity?
The remaining chemical energy in plants after respiration losses.
NPP = GPP - respiratory losses (R).
What is net production of consumers?
The chemical energy stored in food minus losses due to respiration and excretion.
N = I - (F + R).
What is nitrification?
The oxidation of ammonium ions into nitrite and nitrate ions by nitrifying bacteria.
What is nitrifying bacteria?
Aerobic microorganisms responsible for converting ammonium to nitrate ions.
What is the nitrogen cycle?
The process by which nitrogen moves through living organisms and the environment involving nitrogen fixation nitrification ammonification and denitrification.
What is nitrogen-fixing bacteria?
Microorganisms that fix atmospheric nitrogen into usable nitrogen compounds.
What is oxidation?
The loss of electrons or hydrogen or the gain of oxygen.
What is oxidative phosphorylation?
ATP synthesis during the electron transfer chain, using reduced co enzymes and oxygen.
What is the phosphorus cycle?
The movement of phosphate ions between organisms and the environment, involving uptake, digestion, and erosion.
What is photoionisation?
The process where chlorophyll absorbs light exciting electrons to a higher energy level.
What is photolysis?
The splitting of water using light energy during photosynthesis, producing oxygen, protons, and electrons.
What is photosynthesis?
A process where plants convert light energy into chemical energy through light-dependent and light-independent reactions.
What is primary productivity?
The rate of energy fixation by photosynthesis in a given area over time.
What are producers?
Photosynthetic organism that form the base of the food chain by creating biomass.
What is a pyruvate molecule?
A three-carbon molecule formed in glycolysis, converted into acetate during aerobic respiration or lactate/ethanol in anaerobic conditions.
What is reduction?
The gain of electrons or hydrogen or the loss of oxygen.
What is Ribulose bisphosphate?
A five-carbon molecule that reacts with carbon dioxide in the carbon cycle to form glycerate 3-phosphate.
What is rubisco?
The enzyme catalysing the reaction between RuBP and carbon dioxide.
What are saprobionts?
Decomposers that breakdown dead material into simpler organic substances.
What is secondary productivity?
The rate of which consumes convert ingested energy into biomass.
What is substrate-level phosphorylation?
ATP formation by transferring a phosphate group from an intermediate compound to ADP.
What is triose prostate?
A 3-carbon molecule in the Calvin cycle that can form sugars or regenerate RuBP.
What is a trophic level?
The position of an organism within a food chain.
