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.
Membranes allow for compartmentalization of different cellular organelles. Why is this advantageous?
- Specific sets of enzymes responsible for specific biochemical functions can be kept in close proximity to each other. Efficiency of the chemical reactions is increased if concentrated
- Incompatible processes such as synthesis and degradation can be kept separate and not interfere with each other.
Give an example of enzymes that are kept in close proximity of each other
- Chloroplasts contains all the enzymes necessary for photosynthesis
- Mitochondria for aerobic respiration.
Different compartments contain what?
1) A unique set of enzymes
2) Different products (from those enzymes)
What is the advantage of an increased membrane surface?
Increases the potential metabolic capacity across the membrane
True or false: chloroplasts are directly responsible for an increase in the metabolic capacity of aerobic plant cells
False
In plant cells, mitochondria are responsible for cellular respiration
(Chloroplasts contain enzymes for PHOTOSYNTHESIS)
What is the chemical formula for photosynthesis?
CO2+ 2 H2O + light energy –> C6H12O6 + H2O + O2
What is the primary product of photosynthesis?
a) ATP
b) Carbohydrates
c) Oxygen
b) Carbs (ie. glucose)
Oxygen is a byproduct
Describe the cycle of photosynthesis.
Light energy is transformed into chemical energy in the form of ATP and NADPH
Enters the Calvin Cycle where NADPH and ATP are used to drive the reduction of atmospheric carbon dioxide into carbohydrates.
What is the primary source of ATP that fuels our bodily processes?
Carbohydrates
Monosaccharides polymerize via _______ to form disaccharides
Glycosidic bonds
Is galactose a monosaccharide or disaccharide?
Mono
Is sucrose a monosaccharide or disaccharide?
Di
Is maltose a monosaccharide or disaccharide?
Di
Is lactose a monosaccharide or disaccharide?
Di
Is fructose a monosaccharide or disaccharide?
Mono
Where (on the molecules) does the polymerization reaction of carbs usually occur?
On the OH groups on carbon 1 of one molec and carbon 4 on the other molec
What are the two types of glycosidic bonds?
Alpha 1,4 and beta 1,4
What structure forms when many monosaccharides are linked together?
Polysaccharides
Give two examples of polysaccharides
Glycogen
Starch
Describe the chemical structure of starch
Made up of alpha1-4 glycosidic linkages between alpha-glucose monomers
What are the two types of starch?
Amylopectin
Amylose
Describe the difference between amylopectin and amylose
Amylopectin = branched
Amylose = unbranched
Why is there a difference between amylopectin and amylose?
The interactions between neighbouring carbon atoms of each glucose monomer are different
Ex. In amylopectin, the glycosidic bonds form between carbon 6 of one monomer and carbon 1 of the other
When starch is digested, how is it stored in our bodies?
Glycogen
Where is glycogen stored in our bodies?
Liver
Muscles
What is the structure of glycogen like?
Highly branched (more than amylopectin)
What are the main steps, in order, of cellular respiration?
Glycolysis makes two pyruvates in cytosol
Pyruvate turn into acetyl CoA
Acetyl CoA enters mitochondrial matrix
Acetyl CoA processed in Kreb’s cycle
Electron transport chain
How many ATP molecules are made per glucose?
30
Carbohydrates are metabolized first, followed by _____ and then _____
Fats
Proteins
Why is ATP a source of molecular energy?
ATP has three phosphate groups, with four negative charges in close proximity. These negative charges then repel away from each other and give the electrons in the phosphate groups a very high potential energy
What is the process that turns ATP into ADP + a phosphate group?
Hydrolysis
True or false: the hydrolysis of ATP is a highly exergonic reaction.
True
What is the meaning of exergonic?
Release energy in the process
What is the structure of ATP?
Three phosphate groups attached to a ribose sugar and an adenine
What is ATP used for?
Performing mechanical, transport, and chemical work
Transport of substances across a cell membrane AGAINST a concentration gradient
Many enzymes require energy to perform their functions
