Lesson 4: Interconnectedness of living things Flashcards
Compare photosynthesis and cellular respiration?
They are similar: The reactants of photosynthesis are the products of respiration and vice versa; all that changes is the form of energy
photosynthesis: light energy
cellular respiration: electrochemical energy
They occur in different places
photosynthesis: chloroplast
respiration: mitochondrion
What is the energy cycle?
the energy of sunlight captured by photosynthesis goes through transformations into chemical forms. These chemical forms are then released as heat and free energy which are available to the work of the cell in cellular respiration, where some of the energy is also dispersed as heat.
Why are the processes of photosynthesis and cellular respiration interdependent?
Oxygen and sugars produced by plants are used by both plants and animals to get energy; and that CO2 produced by animals is used by plants to make energy.
Similarities between chloroplasts and mitochondria.
- The calvin cycle reactions are like those in the krebs cycle but in reverse
- ETC occurs in both thylakoid and inner mitochondrial membranes and it contains some proteins and cytochromes that are identical or very similar.
- ATP synthase uses proton motive force to power chemiosmosis during the main ATP generation phase, both in the final stage of the light reactions and in the final stage of respiration.
Endosymbiosis and Common Orgins
- both chloroplasts and mitochondria have a double membrane structure and they are the only organelles that have enough DNA to reproduce themselves within a living cell.
Endosymbiotic Hypothesis
This hypothesis states that both organelles are derived from ancient bacteria that became accustomed to living inside other cells.
Explain how the incomplete digestion of absorbed bacteria by larger bacteria can be used as evidence to support the endosymbiotic hypothesis.
If the small bacteria that get absorbed by the larger bacteria are not digested they may be able to continue living inside of the cell, if they produce a product or provide a service that benefits the larger bacteria, then they may be reserved inside the bacteria. This is thought to be the process by which bacterial ancestors to the mitochondria and chloroplasts were absorbed and eventually incorporated into cells
Evaluate this statement: Scientists have proven that cigarettes cause lung and other types of cancer.
Smoking a cigarette is carcinogenic (cancer-producing) and should be avoided, even if we cannot prove a cause and effect relationship in every case.
What does empirical falsification mean?
It means that we can prove a theory to be incorrect, but we cannot prove a theory to be absolutely correct.
Increase in CO2 and other greenhouse gases from natural and human sources is contributing to:
- and increase in air and water temp
resulting in
- changing precipitation patterns
- changing weather patterns
- shift in climate zones
influencing:
- species extinction rates
- increased melting of glacial and polar ice caps
causing:
- water levels to rise and increased coastal flooding to occur
- extreme weather events to occur more often and more severly
How could plants potentially be used to reduce the amount of climate change?
Plants could potentially be used to absorb and store CO2. They could reduce CO2 levels in the atmosphere by removing carbon dioxide from the air through photosynthesis.
C4 plants are able to photosynthesize better than C3 plants at higher temps and higer CO2 levels, so they may be better suited o this role. C3 plants, may of which are staple food crops, may be genetically modified in order to be more efficient users of CO2.
The overall benefits would be the removal of CO2 from the atmosphere, which would lower the heat-trapping greenhouse effect and help to slow the rate of climate change.
