Chloroplasts (100-102 Q) Flashcards
What is a Plastid?
- General class of plant-specific organelles
- Often contain pigments that absorb certain colors of light & makes plants appear colored
What is the most important Plastid?
-Chloroplasts! which is the site for capturing light energy in photosynthesis
What pigment do Chloroplasts have?
-Chlorophyll which makes them appear green
The sun is…
Polychromatic
which means that it can split into different colors= Red, orange, yellow, green, indigo, blue, violet
How do plants get their color?
- 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
How do leaves change colors?
-The reduction of sunlight in the fall & winter months causes the green chlorophyll to break down & the orange color to appear
What is the Structure of a Chloroplast?
- 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
What is the Structure of the Outer & Inner membranes of a Chloroplast?
- The Outer membrane covers the entire organelle
- The Inner membrane ALSO covers entire organelle which makes it a COMPLETE covering not invaginated
What is the 3rd membrane of a Chloroplast?
- 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
What does the Thylakoid membrane of the Chloroplast consist of?
- 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
What is the Stroma component of the Thylakoid Membrane of a Chloroplast?
- Its soluable material inside the inner membrane & outside the grana
- This is where some important chemical reactions occur during photosynthesis
What is the order of membranes from outside the chloroplast to the inside?
-Outer membrane, Inner membrane, thylakoid membrane
What were chloroplasts originally?
-They were also free living & became endosymbionts= lost the ability to live independantly & also their DNA
What did the chloroplasts retain when they became endosymbionts?
-Some DNA & some of their characteristics
What are Chloroplasts?
- 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