47
votes
Does any organism use both photosynthesis and respiration?
tl;dr: Yes, all plants breathe.—
I'm not sure whether I understand the question correctly; because all plants use respiration! Some of the organic high-energy substances produced by ...
41
votes
Accepted
Do photosynthesis and respiration violate the law of conservation of energy?
With slight adjustments to the scientific wording, what the poster states is in effect:
“…to produce one molecule of glucose in photosynthesis, 18 ATP molecules are used up hydrolysed”
and
“…...
- 26.6k
18
votes
Accepted
Is death by cyanide the same as suffocation?
In suffocation or asphyxiation you are actually deprived of breathing oxygen. As a result, the arterial blood oxygen concentration decreases (hypoxemia) which is detected by the chemoreceptors of the ...
- 391
15
votes
Accepted
Does any organism use both photosynthesis and respiration?
Besides the unicellular organisms cited by other answers (and the fact that plants actually do respiration), there are some animals who are able to get, although indirectly, energy from photosynthesis ...
- 346
11
votes
Why is ATP synthase sometimes referred to as ATPase?
The way we were
To understand why you may encounter ATP synthase referred to as ATPase, you need to be aware of the historical context — the experimental work that preceded the knowledge of the ...
- 26.6k
10
votes
Accepted
Why do zoologists classify sponges as animals rather than plants?
Organisms are classified, not by their behavior, but by their phylogeny (evolutionary relationships). Sponges have unique and complex molecules in their intracellular matrix that developed in a common ...
- 7,716
9
votes
Accepted
What are the sources of molecular hydrogen in human breath?
Hydrogen in breath arises from normal intestinal bacteria, mainly in the colon, which break down (ferment) the undigested nutrients that have passed through the small intestine. Hydrogen is absorbed ...
- 8,124
9
votes
Are there land animals that use gill-like organs instead of lungs?
Terrestrial crustaceans are land animals that use gills (or gill-like structures) for gas exchange, though these gills must be kept moist for efficient respiration.
Specifically, animals like hermit ...
- 8,336
8
votes
Cough at 1000 km/h?
This reference from CHEST lists 21 clinically measured peak flow rates during various modes of coughing. Of these patients, and for unassisted cough, the highest peak flow is about 4 liters/sec. The ...
- 866
8
votes
Is death by cyanide the same as suffocation?
I'm not a doctor, so I'm not 100% sure about the physiological differences, but on a molecular level there is one:
Cyanide blocks the complex IV of the oxidative phosphorlytaion, which will directly ...
- 4,401
8
votes
Are there land animals that use gill-like organs instead of lungs?
Some terrestrial hermit crabs (genus Coenobita) have gills, but these are only partially responsible for their respiration1. These animals carry around water with them in the snail shell they 'wear'.
...
- 5,683
8
votes
Why does exhaled air still contain oxygen?
You seem to be confused about diffusion versus bulk flow of fluid (air/gas).
In the lungs, there is diffusion between blood and the gas in the lungs. There is sufficient surface area that these ...
- 47.2k
8
votes
Besides carbon dioxide and water vapor, what waste gases are removed through the human respiratory system?
These sources are understandably couched in their language, but wikipedia is more certain:
All the metabolic wastes are excreted in a form of water solutes through the excretory organs (nephridia, ...
- 10.8k
7
votes
Accepted
How could cyanobacteria survive the anaerobic conditions of ancient earth?
The first cyanobacteria were probably anaerobic, and this matter seems to be a hot topic of contemporary research. A recently published studya that performed a phylogenetic analysis of various ...
- 2,116
7
votes
Accepted
In lichen, do the fungi consume the oxygen produced by algae?
Exchange of gases between lichen symbionts has been demonstrated for Flavoparmelia caperata. Note that this is a foliose lichen species, though the findings may be generalizable to marine lichen.
We ...
- 8,336
6
votes
How much oxygen does a plant use up at night?
Roughly, half of the CO2 assimilated annually through photosynthesis
is released back to the atmosphere by plant respiration (Gifford,
1994; Amthor, 1995).
Source:
https://academic.oup.com/aob/...
- 351
6
votes
Accepted
Where do all the NAD+s come from?
There is of course a pathway that synthesizes NAD+ de novo, usually from tryptophan, aspartic acid or vitamin B3, or salvaged from compounds like nicotinic acid, nicotinamide. You can read more about ...
6
votes
Could humans breathe if the average methane content of the atmosphere increased to 1%?
Methane is biologically inert and can only act as an asphyxiant at high concentrations by displacing oxygen. An environmental exposure limit has been set at 5,000 ppm, though 10,000 ppm (1%) had no ...
- 17.9k
6
votes
Is there any organism that is born with all the nutrients and resources needed for their entire lifetime?
You may need to clarify your question: As written, this would be the biological equivalent of a perpetual motion machine. No such organism could reproduce without either violating the first and second ...
- 5,600
6
votes
Do plants take in the same amount of CO2 as they release?
You've made one faulty assumption: that the second reaction is occuring at the same rate as the first. In fact, plants only burn enough glucose to fuel their activities. Much of the formed glucose is ...
- 2,731
6
votes
Accepted
Do humans emit more carbon through respiration or defecation?
The short answer
In a comparison between exhaled and faecal carbon, exhaled carbon wins.
The long answer
Warning: Assumptions, approximations and averages ahead.
Calculating faecal carbon excretion
...
- 1,307
6
votes
Accepted
Will obligate aerobic bacteria die if placed in a buffer solution even in the presence of oxygen?
Answer
No. There is ample evidence that:
Most non-extremophilic bacteria grow over a broad range of external pH values, from 5.5 – 9.0, and maintain a cytoplasmic pH that lies within the narrow range ...
- 26.6k
6
votes
Why is the partial pressure of oxygen in blood same as that in alveoli
There are three unfounded assumptions in your equation that I can see.
You're treating partial pressure as a concentration. Partial pressures are not concentrations, though they're convenient ...
- 47.2k
5
votes
Accepted
Why do bacteria eat enamel?
While I can't find any specific sources regarding bacteria eating enamel, I highly doubt this is what's happening in our mouths. I doubt this because your point is likely true - minerals in enamel ...
- 183
5
votes
Why does breathing increase in higher temperatures?
As you can see on the diagram below, oxygen solubulity in water drops by increasing temperature, so your fish has to breath more to get the same amount of oxygen.
ref
You can find more info about ...
- 4,462
5
votes
Accepted
Is too much CO2 in the air toxic?
CO2 forms carbonic acid in water, which helps to dissolve rocks and mountains in envitonmental science. It would slightly acidify your body with what is called a weak acid.
5% can cause acidosis and ...
- 10.5k
5
votes
Accepted
How does carbon dioxide diffuse into red blood cells?
The red cell membrane is highly permeable to gases because the molecules of gases are small, uncharged, and soluble in lipids, such as those of a bilayer.The effect of 4,4′-diisothiocyanato-stilbene-2,...
- 181
5
votes
What does this graph explain?
A graph is generally meant to be interpreted as y being a response to a change in x. This graph highlights that as the partial ...
- 68.3k
Only top scored, non community-wiki answers of a minimum length are eligible