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Title: Cellular/Molecular Biology, The Evolution of Cells
Description: These notes are purely lecture notes on the key points that the professor went over. This chapter is about the evolution of cells. Topics included are early life and how early life arose, the Endosymbiont Theory, the difference between eukaryotic and prokaryotic cells, and a brief introduction to some of the most important organelles (although the class ended before he could get through all of them).
Description: These notes are purely lecture notes on the key points that the professor went over. This chapter is about the evolution of cells. Topics included are early life and how early life arose, the Endosymbiont Theory, the difference between eukaryotic and prokaryotic cells, and a brief introduction to some of the most important organelles (although the class ended before he could get through all of them).
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Intro to Cellular & Molecular Biology
Lecture 2: Cellular Evolution: Cells and Organelles
● Introduction
○
○
●
WEEK 1
How old is the planet? How long ago did cellular life first evolve on Earth?
■ Water allowed macromolecules to be synthesized 3
...
■ Oxygen builds up in the atmosphere 2 billion years ago, which allows
prokaryotic organisms to carry out photosynthesis
...
Where did these cells come from?
■ Based on the basic chemicals that volcanoes erupted, these combined to
form less-complex molecules
...
■ Stanley Miller experiment, “make sure you read through this”
● Heated water on the bottom (to mimic magma) connected to
gases on the top… including CO2, NH3, H2O (key: absence of
O2)… He also made lightning apparently which connected and
was fed back into the water
...
● After analyzation, he found that amino acids did form under these
conditions
...
■ Clay and rock were another means to form macromolecules
...
■ Evidence
● RNA is required for DNA replication
...
● Maybe an “RNA” world existed before a “DNA” world
...
■ Basically trapping RNA and forming the first “protocells
...
Prokaryotes can be divided into two groups given ancestral evidence:
■
■
■
But obviously, mainly the difference lies between eukaryotes and
prokaryotes
...
● Made up of RNA and proteins
...
● Cell Size
○
○
Surface area vs
...
■ The rate of diffusion limits the cell size
...
■ General rule: the bigger you are, the more diffusion you need
...
How can diffusion be improved?
■ Eukaryotes can get away with being bigger by using carrier proteins to
actively transport materials throughout the cytoplasm
...
Vesicles in proteins fibers can also act as a quick Uber
...
■ But there aren’t organelles!
“How to draw bacteria on the test”
■ 1
...
Draw DNA in a circle attached to the
cell membrane you drew
...
Draw the other structures:
● Draw hash marks around the
entire thing to represent peptidoglycan (proteins and sugar)
*”know this for the test”
○ Then draw another bilayer around that
● Ribosomes around the DNA part
● Proteins around the DNA part
Eukaryotes, baby!
○
“For the test,” recognize the nucleus, the ER,
■ Notes on the nucleus
● Double membrane to protect DNA
...
● Notice the pores that are on the
nucleus to transport proteins
...
● The nucleolus is inside the nucleus…
synthesizes ribosomes
...
Most eukaryotic cells have hundreds of mitochondria!
They’re mostly found in tissues that have a high demand for metabolic
processes
...
Mitochondria can change shape to fit the needs of whatever they’re doing
...
“Know the origins of where mitochondria came from”
■ The endosymbiont theory!!
●
Mitochondria were free on their own thriving as their own little
bacteria and stuff
...
● The ER!
○
○
Rough ER is rough due to ribosomes that make proteins to be secreted by the
cell
...
But it synthesizes lipids and
steroids
...
Then they
fuse with the membrane and… plop! Yay exocytosis :)
● Lysosome… where things go to die
...
■ Now the cell can use their building blocks to do other things
Title: Cellular/Molecular Biology, The Evolution of Cells
Description: These notes are purely lecture notes on the key points that the professor went over. This chapter is about the evolution of cells. Topics included are early life and how early life arose, the Endosymbiont Theory, the difference between eukaryotic and prokaryotic cells, and a brief introduction to some of the most important organelles (although the class ended before he could get through all of them).
Description: These notes are purely lecture notes on the key points that the professor went over. This chapter is about the evolution of cells. Topics included are early life and how early life arose, the Endosymbiont Theory, the difference between eukaryotic and prokaryotic cells, and a brief introduction to some of the most important organelles (although the class ended before he could get through all of them).