Question

stomata in a nutshell or on a leaf, to be exact...
name: emily wong p62
date: 10/24/2023
ok, lets get it over with. i know you want to say it. are there alotta stomata in a tomata? well, the answer is, it depends which part of the tomato were talking about. stomata (singular: stoma) are are tiny pores or openings that control gas exchange. they are found on green stems and on the upper and lower epidermis of leaves, though there are usually fewer stomata on the upper surface as a means of conserving water (upper leaves face the sun).
cells called guard cells control the opening and closing of the stomata. the guard cells are two bean shaped structures that surround each stoma. the opening and closing of the guard cells regulates the flow of water vapor from the leaf. the loss of water through the stomata is known as transpiration; the rate of transpiration increases on very hot days.
guard cells open and close via osmosis. when there is plenty of water, the guard cells swell and bow out, which opens the stomata. when the water is not as available within the plant, the guard cells deflate, which in turn closes the stomata. this works out well, since this also prevents further water loss.
the stomata are also important for photosynthesis because they allow carbon dioxide into the plant cells, and release oxygen from the plant into the atmosphere. one factor that affects photosynthesis is temperature. if the temperature is too hot, the stomata close off to prevent water loss. not only is water important for photosynthesis reactions, but also for turgor pressure, which causes the plant to stand upright and is a general sign of health. plants in great need of water have little turgor pressure and wilt.

1. what are stomata?

are tiny pores or openings that control gas exchange

1. where are stomata found?

on green stems and the upper and lower epidermis of leaves

1. name 3 gases that stomata allow to enter or leave the plant:
2. what are guard cells?

two bean shaped structure that surround each stoma.

1. how do guard cells open and close?

when there is plenty of water, the guard cell swell and bow out, which opens the stomata. when the water is not as available within the plant, the guard cell deflate, which in turn closes the stomata.

1. what is transpiration?

the loss of water through the stomata

1. examine the graph below. using what you know about the stomata and photosynthesis, explain why the rate of photosynthesis would exhibit this pattern with the varying temperatures.

Explanation:

The graph shows the rate of photosynthesis in relation to temperature. At lower temperatures, as temperature increases, the rate of photosynthesis increases because enzymes involved in photosynthesis (like RuBisCO) work more efficiently. However, at very high temperatures, stomata close (to prevent excessive water loss via transpiration). Since stomata are the entry - points for carbon dioxide (a reactant in photosynthesis), when they close, less carbon dioxide enters the leaf. Also, high temperatures can denature enzymes. So, the rate of photosynthesis decreases.

Answer:

At lower temperatures, increasing temperature enhances enzyme activity (e.g., RuBisCO) for photosynthesis. But at high temperatures, stomata close (to conserve water), reducing \(CO_2\) intake (a key reactant). Also, high temps may denature enzymes. Thus, the rate of photosynthesis first increases with temp (up to an optimal point) then decreases.