Introduction to Biology
The portion of a photosystem that contains the light-harvesting pigment molecules is called the ______.
antenna complex
What is the function of a photosystem?
capture photons of light energy
The function of the light-dependent reactions is to ______.
capture solar energy and use it to make ATP and NADPH
Given the following statements, choose the one that most closely describes the process of photosynthesis.
captures solar energy and makes it available to living organisms
ATP provided by ______ powers the reactions of the Calvin cycle, and NADPH provided by ______ is a source of electrons and hydrogens for the Calvin cycle.
chemiosmosis; the electron transport chain of photosystem I
The molecule that is embedded in the thylakoid membranes within chloroplasts and that is able to absorb light is called ______.
chlorophyll
In plants, the molecules capable of absorbing visible light are ______.
chlorophyll and some alternative pigments
The organelle in the mesophyll cells of a plant where the energy of light is absorbed is the ______.
chloroplast
Where are light-absorbing pigments found within chloroplasts?
embedded in the thylakoid membranes
The Calvin Cycle is a series of reactions that produces ______ from CO2 and the products of the light-dependent reactions.
organic molecules
What is synthesized as protons pass through ATP synthase?
ATP
The light-dependent reactions both capture solar energy and produce ______.
ATP and NADPH
Select all of the following that describe the light-independent reactions.
ATP and NADPH are used in the stroma. Carbohydrates are produced. CO2 is used in the Calvin Cycle.
The enzyme that functions in the production of ATP during photosynthesis is ______.
ATP synthase
Place the stages of photosynthesis in order according to when they occur, beginning with the first stage at the top.
1. Capture of light energy 2. Using energy to make ATP and NADPH 3. Formation of organic molecules from atmospheric CO2
In what carbon fixation pathway does CO2 combine with a three-carbon molecule to produce a four-carbon molecule called oxaloacetate?
C4 photosynthesis
What are the products of photosynthesis?
C6H12O6, H2O, and O2
What type of plants minimize photorespiration by fixing CO2 into molecules at night and then closing the stomata during the day while CO2 is regenerated for the Calvin cycle in mesophyll cells?
CAM plants
What are the reactants of photosynthesis?
CO2, H2O, and light energy
What happens during the light-independent reactions, also called the Calvin Cycle?
Glucose is produced.
How does chlorophyll function in photosynthesis?
It absorbs energy from light.
Select all of the following that are true about the electron that reaches photosystem I from photosystem II.
The electron receives another boost of energy from a photon. The electron still has around 50% of its boosted energy.
Select all of the following that are true about photosystems.
They act as antennae for capturing light energy. Chlorophyll molecules are held in a specific location by proteins. Chlorophyll molecules are arranged in a precise pattern.
Match each of the following structures in a chloroplast with its correct description.
Thylakoid-Internal membrane that is a flattened sac Stroma-Semi-liquid that fills interior of chloroplast Grana-Stacks of thylakoids
In the light-dependent reactions of photosynthesis, how many photosystems do plants and algae use in series?
Two
What is a photosystem?
a cluster of chlorophyll molecules arranged in a network
In the C4 pathway, carbon is first fixed to produce ______.
a four-carbon molecule
What is a photon?
a packet of light energy
In plants, both chlorophyll and some alternative pigments ______.
absorb visible light
After solar energy is absorbed by a pigment molecule, what is passed between pigment molecules in a photosystem?
energy
In photosynthesis, when an electron is boosted to a higher energy level, ______.
energy has been captured
CAM plants minimize photorespiration by ______.
fixing CO2 into molecules at night and then using high levels of CO2 to drive the Calvin cycle during the day
The products of the light-dependent reactions are used ______.
in the Calvin cycle
The enzymes and other proteins that are found in the stroma of the chloroplast function ______.
in the assembly of organic molecules
Chloroplasts are organelles in plant and algal cells where ______.
light is absorbed and photosynthesis is conducted
Once it has been absorbed by a pigment, the energy from light is ______.
passed from one pigment to another in the photosystem
Light consists of tiny packets of energy called ______.
photons
In ______, rubisco binds oxygen instead of carbon dioxide, and CO2 is the ultimate product, which is essentially the reverse of the Calvin cycle.
photorespiration
The process carried out by plants and algae that converts solar energy into chemical energy available to almost all living organisms is called ______.
photosynthesis
During photosynthesis, the structure that consists of an arrangement of chlorophyll molecules that capture solar energy is called a ______.
photosystem
In plants, what photosystem acts first in the light-dependent reactions?
photosystem II
In the thylakoid membranes of chloroplasts, proteins and pigment molecules are arranged into complexes called ______.
photosystems
Chloroplasts are able to absorb light because they contain molecules called ______.
pigments
Select all of the following that are stages of photosynthesis.
production of ATP and NADPH capture of light energy Calvin cycle
The assembly of organic molecules from carbon dioxide is carried out by ______.
proteins and enzymes found in the stroma
Photorespiration is the term used to describe when ______.
rubisco binds oxygen and the reverse of the Calvin cycle takes place
Within the chloroplast, a semi-liquid substance called ______ fills the interior and contains enzymes that act to assemble organic molecules. Also present are numerous internal membranes called ______.
stroma; thylakoids
The assembly of new organic molecules occurs during a stage of photosynthesis called ______.
the Calvin cycle
When an electron arrives at photosystem I from the first electron transport chain, what boosts the electron's energy to a very high energy level?
the absorption of another photon of light energy
When a molecule absorbs energy, this causes an electron to move ______.
to a higher energy level