Theme 1- Module 2 Flashcards
What are the structural similarities between prokaryotic cells and eukaryotic cells?
External membrane
What are the structural differences between prokaryotic cells and eukaryotic cells?
Eukaryotic cells
- internal network of membranes
- double membrane bound nucleus (separates the genetic material from the rest of the cell)
Prokaryotic cells
- lack a nucleus
- few to no organelles
What did the appearance of the first photosynthetic cells bring to the Earth?
Oxygen
What were the earliest eukaryotes like?
Single-celled organisms
Contained organelles and internal membrane
systems with distinct structures and functions
Describe the structure of a typical chloroplast
Double membrane around its exterior
Interior filled with flattened and stacked membranes called thylakoids (organized into piles called grana)
What are stacks of thylakoids called?
Grana
Where is chemical energy stored after photosynthesis?
Bonds of carb molecules
How many membranes does mitochondria have?
2
What is the difference between the two membranes?
Outer membrane surrounds cell
Inner membrane connected to cristae
Where is most ATP synthesized in eukary cells?
Mitochondria (animals)
Chloroplasts (plants)
Dr. Lynn Margulis proposed what theory?
Prokary cells entered into host cell where it developed mutually beneficial interactions with eukary
These interactions became vital for the the host cell
Why would it have been advantageous to develop this endosymbiotic relationship (in the example of mitochondria)?
Early earth was a hostile, low oxygen environ
Anaerobic eukaryotes engulfed aerobic bacteria . Bacteria supplied ATP to euk and euk supplied protection for bacteria and a supply of carbon compounds
Evidence that mitochondria came from bacteria that took up residence in proto-euk cells?
Mitochondria…
- look like bacteria
- same size as bacteria
- have own circular genome
- produce enzymes for protein synthesis
Describe the endosymbiotic theory of organelle evo
Invaginations of the cell membrane allowed ancestral prok with genetic information to compartmentalize it into a nucleus.
This allowed them to control the regulation of genes and syn of proteins. Thus became the ancesteral euk
Overtime they became hosts to aerobic prok (mitochondria) and photosyn prok (chloroplasts)
Do all eukaryotic cells have mitochondria?
Yes
Do all eukaryotic cells have chloroplasts?
No
The endosymbiotic theory suggests that chloroplasts evolved from what?
Photosynthetic cyanobacteria that were engulfed by predatory cells
What significance do the green algae Cymbomonas play in the context of endosymbiotic theory?
It’s a living example of an acquired endosymbiotic relationship
They acquire the ability to engage in photosynthesis only after they have engulfed photosynthetic bacteria that perform these functions.
Describe the behaviour of the Cymbomonas and how it relates to endosymbiotic theory.
Living bacteria inside the protists (algae) share their photosynthetic products with the algae host.
Describe the endosymbiotic behaviour of coral and dinoflagellates
Dinoflagellates photosynthesize and release almost all of the products to the coral.
Describe the endosymbiotic behaviour of sea slugs and algal cells
Sea slug consumes photosynthetic algae and harvests the chloroplasts from the algal cells.
The chloroplasts are maintained in the cells of the sea slug.
Are the relationships of the coral and the sea slug permanent or temporary?
Temporary
True or false: the endosymbiotic theory states that these temporary relationships (ie. coral and sea slug) are permanent and nonheritable.
False: these relationships are permanent and HERITABLE
Evidence that shows that these temporary relationships are permanent and heritable?
- Both mitochondria AND chloroplasts contain their own circular genomes (such as found in bacteria)
- Analysis of the genes and proteins show significant similarity to those of bacteria.
