A photosynthesis It is a metabolic process, that is, a function of the organism, carried out by beings from the plant kingdom, algae and cyanobacteria.
The purpose of photosynthesis is the production of glucose (carbohydrate) through light energy. Therefore, these organisms are able to produce a store of energy from light.
1 - Main pigment capable of converting, primarily through resonance, light energy into biological energy?
A) Chlorophyll
B) Chloroplast
C) Granum
D) Thylakoid
E) Vacuole
Right answer. Letter a - Chlorophyll.
This question raises doubts when the student quickly studies the subject, as chloroplast and chlorophyll may appear, to an inattentive eye, to be the same structures.
However, chloroplast is the organelle that has an abundance of chlorophyll molecules.
There are different types of chlorophylls, the type B It is The. Chlorophyll b transmits the energy of the photon received by resonance, until it reaches chlorophyll a, causing it to lose 2 electrons.
2 - The purely chemical phase of photosynthesis is known as _______ and in it the use of __________ occurs to produce____________.
A) light phase / glucose / ATP
B) Calvin/ATP/glucose cycle
C) dark phase / glucose / ATP
D) Krebs cycle / ATP / glucose
E) Calvin cycle / glucose / ATP
Right answer: Letter B - Calvin/ATP/glucose cycle.
There are two phases in photosynthesis, the first is known as the light phase.
In it, light plays a large role in the processes of water photolysis (breakdown of the water molecule to form O2 to release into the atmosphere) and production of oxygen gas.
The second is the dark phase or Calvin cycle, in which ATP and electron transport molecules (NADPH) are used up.2) to produce glucose.
3 - There are factors that directly influence the photosynthesis rates of an autotrophic organism. Mark the correct option.
A) Excessive winds
B) Clouds in front of the sun
C) High temperature
D) Bad soil
E) Lots of plants around
Right answer: Letter C - Elevated temperature.
In photosynthesis there is the participation of enzymes, proteins with biochemical function, which denature, that is, lose their biological function at high temperatures.
Which will cause inefficiency in the biochemical processes of photosynthesis.
4 - Do organisms from the Plant Kingdom only perform photosynthesis in the morning and respiration at night?
Ah yes! Photosynthesis in the presence of light and respiration in the absence of light
B) No! Photosynthesis in the absence of light and respiration in the presence of light
C) No! Photosynthesis in the presence of light and respiration only in the presence of light
D) Yes! Photosynthesis in the presence of light and respiration only during the day
And not! Photosynthesis with variable intensity during the presence of light and constant respiration throughout the day.
Right answer: Letter e - No! Photosynthesis with variable intensity during the presence of light and constant respiration throughout the day.
Photosynthesis only happens in the presence of light rays, whether natural or artificial, however, respiration is a process that occurs in the capture of O2 and release of CO2.
Plants also breathe, however, not just at night, but throughout the day.
This confusion is common, as photosynthesis does not occur naturally at night, given the absence of sunlight, leaving only respiration (aerobic).
5 - What wavelengths do chlorophylls a and b absorb best?
A) Violet/blue and red bands
B) Violet and orange bands
C) Blue and yellow bands
D) Green and red bands
E) Violet and green bands
Right answer: Letter a - Violet/blue and red bands.
Light is an electromagnetic wave, therefore, it carries energy. There are varying lengths within white light and these lengths give the colors observed in nature.
In organs that carry out photosynthesis, the green color is perceived, as the green wavelength is reflected on their surface, therefore it is not used for photosynthesis.
The best lengths are 460 to 500 nanometers with a color between violet and blue and 680 to 700 nanometers with a red color.
6 - (FUVEST - SP) In a certain light condition (photic compensation point), a plant returns to the environment, in the form of carbon dioxide, the same amount of carbon that fixes, in the form of carbohydrates, during photosynthesis.
If the photic compensation point is maintained for a certain time, the plant:
A) dies quickly because it cannot get the energy supply it needs
B) continues to grow, as it maintains the capacity to store the food it synthesizes
C) continues to grow, as it maintains the capacity to store the food it synthesizes
D) continues to live, but does not grow, as it consumes all the food it produces
E) continues to live, but does not grow, as it loses the ability to extract the nutrients it needs from the soil
Right answer: Letter D - continues to live, but does not grow, as it consumes all the food it produces.
When the rates of respiration and photosynthesis are equal, the phenomenon of photic compensation. This means that photosynthesis, responsible for producing energy reserves (glucose) for the plant, does not surpass respiration (metabolic reaction of glucose consumption).
If there is no reserve, the plant does not grow, but remains alive. However, if the respiration rate exceeds the photosynthetic rate, the plant will die.
7 - (UFCG-PB) In the presence of light, the plant carries out the photosynthetic and respiratory processes. The production of O2 in photosynthesis it is often greater than its consumption in the respiratory process. In this case, it can be said that the plant is responsible for contributing to atmospheric oxygenation. However, the plant, in the absence of light, only breathes by releasing only CO2 In the atmosphere.
Select, among the alternatives below, the one that represents the correct sequence of the photosynthetic and respiratory processes.
A) breakdown of CO2 and release of O2 / production of ATP and NADP++ / glycolysis / Krebs cycle and CO release2 Calvin cycle and sugar production/ATP and NADP production++ / respiratory chain
B) hydrolysis and release of O2 / production of ATP and NADP++ / Calvin cycle and sugar production / glycolysis / Krebs cycle and CO release2 / respiratory chain
C) production of ATP and NADP++ / CO break2 and release of O2 / glycolysis / Krebs cycle and CO release2 /Calvin cycle and sugar production / ATP and NADP production++ / respiratory chain
D) hydrolysis and release of O2 / Calvin cycle and sugar production / glycolysis / respiratory chain / production of ATP and NADP++ / Krebs cycle and CO release2
E) breakdown of CO2 and release of O2 / production of ATP and NADP++/ Krebs cycle and CO release2 / Calvin cycle and sugar production / respiratory chain / ATP and NADP production++ / glycolysis
Right answer - Letter B.
First of all, we need to keep in mind that, in a way, photosynthesis and respiration are two antagonistic metabolic processes. Therefore, one produces (synthesizes) an energy reserve and the other consumes this reserve.
Having said that, let's see what happens in the resolution:
To be able to breathe, the plant must first produce, therefore, photosynthesis must happen first.
First the water (H2O) undergoes photolysis (breakdown by light), after which energy-carrying molecules (ATP and NADP) are produced++).
From this moment on, the Calvin cycle (Carbon fixation) can occur, as this requires energy expenditure, that is, ATP and NADP molecules.++ produced will be used to produce sugar.
Now, yes, the plant can breathe. Glucose will enter cells and undergo glycolysis (a set of 10 chemical reactions in the cytoplasm), then go to the mitochondria to go through the Krebs cycle, releasing CO2, and, finally, reach the respiratory chain (oxidative phosphorylation).
8 - Consider the following statements regarding the process of photosynthesis:
I - Corresponds to a process of transforming the sun's energy into chemical energy contained in organic molecules.
II - Uses CO2 and H2O as raw materials and releases O2, which comes from CO molecules2.
III - It occurs entirely within the chloroplasts, unlike aerobic respiration, which occurs entirely in the hyaloplasm of the plant cell.
Please tick:
A) if only I is correct
B) if only II is incorrect
C) if only I and II are incorrect
D) if only II and III are correct
E) if all are correct
Right answer: Letter a - if only I is correct.
Photosynthesis is the conversion of electromagnetic energy, present in light, into chemical energy, contained in organic molecules.
However, the O2 released in photosynthesis does not originate from CO2, but from water (H2O).
The same occurs with aerobic respiration, which is not completely carried out in the hyaloplasm (cytoplasm). It occurs in the hyaloplasm (glycolysis) and in the mitochondria (Krebs cycle and oxidative phosphorylation).
9 - The lead vine is a yellowish vegetable, completely devoid of chlorophyll. In this case, how is it possible for this species to store carbohydrates?
A) It is a vegetable, therefore it carries out photosynthesis to store carbohydrates
B) The species in question is holoparasitic, that is, it has haustoria for its nutrition
C) It carries out a small portion of photosynthesis and another part is consumed through haustoria
D) It has authorial roots, therefore it carries out its nutrition through light normally
E) Obtains all the necessary nutrients from the soil
Right answer: Letter B -The species in question is holoparasitic, that is, it has hastoriums for its nutrition.
Contrary to popular belief, there are plants that do not carry out photosynthesis. This only happens in the case of integral parasitic plants or holoparasites.
These plants, like the lead vine, have special roots called haustoria that penetrate the sap-conducting vessels (xylem and phloem) of their hosts and obtain their nutrients from there.
10 - After the photosynthesis process, the sugars produced (C6H12O6) are stored in what form in vegetables?
A) In amyloplasts
B) In reticular vacuoles
C) In chloroplasts
D) In mitochondria
E) In lysosomes
Right answer: Letter a - In amyloplasts.
There are leucoplasts, that is, granules without pigments responsible for storing the carbohydrates produced.
Bibliographic references
UZUNIAN, A.; BIRNER, E. Biology: single volume. 3rd ed. São Paulo: Harbra, 2008.
