Chloroplasts (100-102 Q)

Question 1

What is a Plastid?

Answer 1

• General class of plant-specific organelles

- Often contain pigments that absorb certain colors of light & makes plants appear colored

Question 2

What is the most important Plastid?

Answer 2

-Chloroplasts! which is the site for capturing light energy in photosynthesis

Question 3

What pigment do Chloroplasts have?

Answer 3

-Chlorophyll which makes them appear green

Question 4

The sun is…

Answer 4

Polychromatic

which means that it can split into different colors= Red, orange, yellow, green, indigo, blue, violet

Question 5

How do plants get their color?

Answer 5

• Well the sun is polychromatic so it spilts into many colors
• Different plants contain different pigments that absorb certain colors for EX carotene (form of Vitamin A) absorbs blue/violet spectrum which leaves orange color to reflect back= in carrots

Question 6

How do leaves change colors?

Answer 6

-The reduction of sunlight in the fall & winter months causes the green chlorophyll to break down & the orange color to appear

Question 7

What is the Structure of a Chloroplast?

Answer 7

• Resembles a mitochondria bc of the similar bullet shape & having multiple membranes
• It consists of inner & outer membranes, a 3rd membrane, disks, granum, grana, stroma

Question 8

What is the Structure of the Outer & Inner membranes of a Chloroplast?

Answer 8

• The Outer membrane covers the entire organelle

- The Inner membrane ALSO covers entire organelle which makes it a COMPLETE covering not invaginated

Question 9

What is the 3rd membrane of a Chloroplast?

Answer 9

• Called the Thylakoid membrane which is greatly folded & shaped into disks that increases surface area
• This is where the business end of the chloroplast takes place

Question 10

What does the Thylakoid membrane of the Chloroplast consist of?

Answer 10

• Since a thylakoid membrane are stacked disks
• A single disk is thylakoid disk
• A stack of thylakoid disks are granum
• And several stacks are called grana
• Space between inner membrane & thylakoids are Stroma

Question 11

What is the Stroma component of the Thylakoid Membrane of a Chloroplast?

Answer 11

• Its soluable material inside the inner membrane & outside the grana
• This is where some important chemical reactions occur during photosynthesis

Question 12

What is the order of membranes from outside the chloroplast to the inside?

Answer 12

-Outer membrane, Inner membrane, thylakoid membrane

Question 13

What were chloroplasts originally?

Answer 13

-They were also free living & became endosymbionts= lost the ability to live independantly & also their DNA

Question 14

What did the chloroplasts retain when they became endosymbionts?

Answer 14

-Some DNA & some of their characteristics

Question 15

What are Chloroplasts?

Answer 15

• Site for photosynthesis
• So they absorb light energy from the sun (the greatest source of energy)
• And then they convert that light energy into chemical energy through photosynthesis

Question 16

What is the process for photosynthesis?

Answer 16

• Light energy from the sun is used tor reduce carbon dioxide to make reduced carbon compounds that store chemical energy
• Those reduced carbon compounds have many H’s & little O’s & these include plant carbs, proteins & oils
• We then eat these reduced carbon compounds (directly & indirectly) & reoxidize them in our mitochondria to make energy for us

Question 17

Simplified version of photosynthesis go!

Answer 17

-Chloroplasts take energy from the sun—> store it in reduced compounds—> we eat those reduced compounds—> those compounds then get oxidized in our mitochondria—> results in energy to keep us livin’

Question 18

What happens in Organic Photosynthesis?

Answer 18

-CO2 is reduced by taking electrons from water which releases oxygen