Chapter 10 Flashcards
(71 cards)
What is photosynthesis?
The process that converts solar energy into chemical energy within chloroplasts.
What does photosynthesis do?
Nourishes almost the entire living world directly or indirectly.
What are autotrophs?
“Self-feeders” that sustain themselves without eating anything derived from other organisms.
What do autotrophs do?
They are the producers of the biosphere; they produce organic molecules from other inorganic molecules.
Are all plants photoautotrophs?
Almost all; photosynthesis also occurs in algae, certain other protists, and some prokaryotes.
What are some examples of photoautotrophs?
Plants, cyanobacteria, multicellular algae, unicellular protists, and purple sulfur bacteria.
What are heterotrophs?
They obtain organic material from other organisms, and are the consumers of the biosphere.
What do heterotrophs do to obtain their food?
Some consume other living things, others (decomposers) eat dead organic materials or feces.
What are fossil fuels made from?
The remains of organisms that died hundreds of millions of years ago, representing ancient stores of the sun’s energy.
What do almost all heterotrophs depend on?
Photoautotrophs; either directly or indirectly for food.
What are chloroplasts?
Organelles that are structurally similar to and likely evolved from photosynthetic bacteria. The structural organization of these organelles allows for the chemical reactions of photosynthesis.
What contains chloroplasts?
Plants and other photosynthetic organisms.
Where does most photosynthesis occur?
In the leaves.
Where are chloroplasts found in?
The cells of the mesophyll, the interior tissue of the leaf.
What are stomata?
Pores that exit the leaf through microscopic openings on the epidermis.
What transports water from the roots and exports sugar to other parts of the plant?
Veins.
What is stroma?
A dense fluid that is surrounded by two membranes.
What are thylakoids?
Connected sacs in the chloroplast that compose a third membrane system. They may be stacked in columns called grana.
What is chlorophyll?
The pigment that gives leaves their green color, resides in the thylakoid membranes.
What is the chemical equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What can the overall chemical change during photosynthesis be described as?
The reverse of cellular respiration.
What is photolysis?
Photolysis (‘light’ and ‘split’): light energy and catalysts interact to drive the splitting of water molecules into protons (H+), electrons, and oxygen gas
What do all photosynthetic organisms require?
A hydrogen source, but the source can vary among organisms.
Ex. sulfur bacteria uses water and forms yellow globules of sulfur as a waste product.
What does photosynthesis do compared to cellular respiration?
Reverses the direction of electron flow compared to respiration.