Subtopics are highlighted, terms are bolded, and definitions are underlined :)
Parts of the Leaf:
Mesophyll - the area of the leaf where chloroplasts are concentrated
Stomata - pores in the leaf in which carbon dioxide enters and oxygen leaves
Guard Cells - open and close the stomate
Epidermis - the outermost tissue layer of the leaf; it also secretes the cuticle
Cuticle - layer of wax that prevents water loss
Veins - vascular tissue
Xylem - transports water from the roots to the leaves
Phloem - transports sugar from the leaves to the roots, shoots, and fruits
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What is Transpiration?
Transpiration is a process of water movement within the xylem of a plant from the root, to the leaf and out the stoma.
What is the benefit of opening the stomata during photosynthesis?
Opening the stomata helps the plant take in carbon dioxide and release oxygen.
What does a plant want to close some or all of the stomata?
Eventually closing their stomata prevents the plant from losing too much water. If they left their stomata open, evaporation would cause them to lose water.
Chloroplast:
Photosynthesis:
What is photosynthesis?
Photosynthesis is a process by which plants convert light energy into chemical energy or carbohydrates. It takes place in the chloroplasts.
There are two main stages of photosynthesis...
Stage 1: Light Reaction
This stage occurs in the thylakoids of the chloroplast. Light is absorbed by plant pigments such as chlorophyll and carotenoids. Water is then broken down and oxygen is released. That converts light energy into chemical energy. ATP, NADPH, and oxygen are formed.
Chlorophyll - main plant pigment that captures the light energy inside the thylakoids. This pigment gives plants their green color.
What is the plant's benefit in having different color pigments?
Different color pigments mean that more light energy can be absorbed since different color pigments absorb different wave lengths.
Stage 2: Calvin Cycle
It takes place in the stroma of the chloroplast. It uses ATP and NADPH formed from light reactions along with carbon dioxide from the air in order to form carbohydrates.
This is why plants take in carbon dioxide (during stage 2) and let out oxygen (during stage 1) as a waste product.
The Carbon Cycle:
Photosynthesis, Cell Respiration, and Combustion form the basis of the carbon cycle.
Cell Respiration - a chemical process that breaks down organic compounds such as carbohydrates in the presence of oxygen and uses the energy released from this process to form ATP
Combustion - the burning of organic matter (ex. wood or fossil fuels)
Combustion releases carbon dioxide into the air.
Greenhouse Gases - gases such as water vapor, carbon dioxide, nitrous oxide, and methane which trap energy from the sun and prevent it from leaving the planet and therefore increase the temperature of the planet
Greenhouse Effect - the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide and methane for example) trap energy from the sun
Without these gases, heat would escape back into space and Earth's average temperature would be colder. The increase in Earth's temperature due to burning greenhouse gases is also known as global warming.