Light/Pigments, Reactions of Photosynthesis, Chloroplast Structure, & Leaf Structure

What is ATP?

ATP stores energy until a cell needs it, and when it does require the energy, it breaks part of the ATP molecule to release energy.

Name the three parts (in order): The molecule on the top left, the molecule in the center, and the three groups on the right

Adenine, ribose, phosphate groups

What happens in ATP Decomposition?

The third phosphate group from the ATP molecule, releasing energy. The leftover molecule is ADP.

What is ADP?

Consists of adenine, ribose sugar, and two phosphate groups. Has less energy than ATP.

What happens during ATP Synthesis?

ADP it turned into ATP. To reattach a lone phosphate group to the other two phosphate groups in ADP, it requires glucose.

Where is energy stored within ATP?

Within the bonds of the three phosphate groups

What is the photosynthesis equation? (Format: (reactants) (requirements for transition to products [aka the arrow]) (products))

6H₂O + 6CO₂ (sunlight and chlorophyll) 6O₂ + C₆H₁₂O₆

What are autotrophs?

Beings that make their own food (plants)

What are heterotrophs

Beings that obtain food (animals)

What are photoautotrophs?

Beings that use sunlight to make their own food through photosynthesis

How much energy do shorter wavelengths have? What are examples of long wavelengths?

have more energy. Examples: gamma rays and X-rays

How much energy do longer wavelengths have? What is an example of a long wavelength?

Have less energy. Examples: radiowaves

What is the electromagnetic spectrum? How many nm?

The spectrum that contains visible light. 380 nm to 750 nm

What is sunlight made up of?

All visible wavelengths

What are pigments? Do we see absorbed colors or reflected colors?

Molecules that absorb certain wavelengths and reflect others. We see reflected colors.

What is chlorophyll(s)? What colors do they reflect and absorb?

Main photosynthetic pigments, all plants have chlorophyll a or b. Absorbs blue and red wavelengths and reflects green and yellow wavelengths

What are accessory pigments?

Help absorb other wavelengths

Carotenoids

Accessory pigment that reflects red and orange

Xanthophylls

Accessory pigment that reflects yellow

Why do leaves change color in autumn?

Shorter days and cooler temps causes chlorophyll to break down. Accessory pigments can be seen

What is necessary for photosynthesis to occur (what do plants intake)?

Water, carbon dioxide, and sunlight.

What gas do plants give off during photosynthesis (what do plants output)?

oxygen

How does carbon dioxide enter the leaf?

Through the stomata

How does the plant break apart water molecules?

Using sunlight as energy

Is sunlight necessary for plants to stay alive?

Yes, however, if sugar water is given to the plant, it can temporarily survive.

Is oxygen necessary for plants to stay alive? Why?

Yes, it is used to breakdown the carbohydrate molecules that plants use for food. The plant would starve without oxygen.

Glucose formula?

C₆H₁₂O₆

Where is chlorophyll stored?

The chloroplast

What molecules are used for glucose to be made in photosynthesis?

Water molecules are split into separate oxygen and hydrogen atoms, in which excess oxygen is filtered out the leaf while hydrogen bonds with carbon dioxide.

What two colors do chlorophyll a absorb the most?

Violet and red

What two colors does chlorophyll b absorb the most?

Blue and red

What do chlorophyll a and b absorb the least (reflect)

green

Site of photosynthesis?

chloroplast

What is the thylakoid membrane?

disk-like stacks of inner membrane; contain pigments and enzymes; site of light dependent reactions; in the chloroplast

What is the stroma?

Fluid filled space; contains enzymes and DNA; site of light independent reactions; in the chloroplast

What is Grana?

Stack of thylakoid membranes; in the chloroplast

What are photosynthetic pigments?

Found within the thylakoid membrane of the chloroplast; absorb light for photosynthesis; include chlorophyll

What is used in light independent reactions?

ATP and NADPH

Where is glucose made? With what energy? What kind of reaction is it?

In the stroma of the chloroplast; with ATP and NADPH; light independent reaction

Where is excess oxygen produced in during photosynthesis? What kind of reaction is it?

The thylakoid membrane of the chloroplast; light dependent reaction

Light dependent reaction process? Ultimately, what are the three products?

Chlorophyll absorbs light to split water into oxygen and hydrogen atoms. Oxygen gas is given off as a byproduct. Ultimately, O₂, ATP, and NADPH are the products.

How are ATP and NADPH formed? What are they used for?

From light dependent reactions, and are then used in light independent reactions

What are light independent reactions also called?

The Calvin Cycle

Can light independent reactions use light?

Yes, with or without light.

Light independent reaction process?

Carbon dioxide from the environment combines with ATP and NADPH from light reactions to make glucose

What is glucose used for in light independent reactions?

To make sucrose, cellulose, other carbohydrates, lipids, proteins, and more

What is photolysis?

Process of water being split by light

What is the main photosynthetic organ of the plant?

The leaf

Answer in alphabetical order: (From A to K)

Vein, cuticle, upper epidermis, mesophyll, palisade mesophyll, chloroplast, spongy mesophyll, lower epidermis, air space, stomata, guard cell.

Why (in flowering plants) are leaves flat?

To maximize light absorption and control gas exchange

What covers the upper surface of leaf-functions in protection and secretes the cuticle?

The upper epidermis

What is the opening or pore in the epidermis that allows for diffusion of gases and water vapor?

stomata

What consists of xylem and phloem tissues and supplies water and minerals to leaf and carries products of photosynthesis to other plant parts?

the vein/vascular bundle

What holds air?

air space

What is the mesophyll layer that contains the most chloroplasts, where most photosynthesis occurs?

Paliside mesophyll

What is the mesophyll layer that contains air spaces for gas storage?

Spongy mesophyll

What is the waxy coating that prevents drying out and protects the leaf?

Cuticle

What covers the lower surface of the leaf-functions in protection and secretes the cuticle?

Lower epidermis

What is the tissue that contains the palisade and spongy layers?

mesophyll

What surrounds the stomata to open and close them in response to environmental conditions, as well as permit gas exchange and regulate water loss?

Guard cells

What is the site of photosynthesis and has chlorophyll and other pigments for light absorption?

Chloroplast

What is the vascular tissue that transports sugars throughout the plant?

Phloem

What is the vascular tissue that transports water and minerals throughout the plant?

Xylem

What happens when the stomata are open (why does it open)?

Carbon dioxide can diffuse in and oxygen gas can diffuse out the leaf.

Why does the stomata close?

Water is lost to evaporative forces when the stomata are open. It would close in hot/dry environments.

When are stomata open?

They remain open in the day when photosynthesis is occurring and sugars are being made, and oxygen is being created that has to be diffused out. However cacti have their stomata open at night when temps are low to minimize evaporative water loss.

What is evaporative water loss from leaves and other aboveground plant parts called?

Transpiration

How are guard cells regulated?

Through osmosis. When in a hypotonic environment, guard cells swell, forming a gap and opening the stomata (takes in water). When in a hypertonic environment, to conserve water, guard cells lose water and close the gap (holds water).

Relationship of light intensity/concentration of carbon dioxide to the rate of photosynthesis

Both are necessary for photosynthesis to occur, and the rate will exponentially increase with both factors. However, to a certain extent, it will barely increase the rate of photosynthesis.

Relationship of temperature to the rate of photosynthesis

The rate of photosynthesis will increase while temperature is increasing until before 30 C, in which it will then decrease until 40 C, when the rate is 0.