Lecture 4 - Cells Flashcards
Cytosol vs Cytoplasm
Cytosol is the liquid interior of the cell.
Cytoplasm is the cytosol + the organelles and internal structures
Prokaryotic vs Eukaryotic Cells
Eukaryotic Cells have a membrane-bound nucleus and organelles whereas Prokaryotic Cells do not.
Which 2 Domains Contain Prokaryotes?
Archaea & Bacteria
Most bacteria have a cell wall. One genus that is an exception to this is _______.
Mycoplasma
Cytoskeleton
the protein scaffolding that helps cells hold their structure and may help facilitate movement.
Organelles
Are found only in eukaryotic cells.
Essentially are mini-organs for the cells to carry out different functions.
Do Prokaryotes have organelles?
No
Do Eukaryotes have organelles?
Yes
Plasma Membrane AKA
Phospholipid Bilayer
Do Eukaryotes have a plasma membrane?
Yes
Do Prokaryotes have a plasma membrane?
Yes
two parts of a phospholipid
- hydrophilic phosphoric head
- hydrophobic fatty-acid tail
What molecules can pass through the plasma membrane on their own?
Small, non-polar molecules.
Passive Transport vs Active Transport
Passive Transport does not require any Energy (ATP) to move the molecules across the membrane whereas Active Transport does.
What is the energy source within cells?
ATP
(adenosine triphosphate)
Diffusion
small, non-polar molecules can passively cross the plasma membrane anywhere along the membrane
Facilitated Diffusion
larger, polar molecules can passively cross the plasma membran through a transport protein.
Osmosis
the passive diffusion of WATER across the plasma membrane
Passive Transport
molecules move from areas of high concentration to areas of low concentration
(molecules move down the gradient like a boulder rolling down a hil)
Active Transport
ATP (energy) is used to move molecules from areas of low concentration to areas of high concentration
(molecules move up the gradient like someone carrying a big rock up a hil)
Isotonic Solution
equilibrium
the concentration of the solution is equal to the concentration inside the cell
Hypotonic Solution
cellswells #likeahippo
the concentration of the solution is less than the concentation inside the cell
Hypertonic Solution
cellshrivels
the concentration of solution is greater than the concentration inside the cell
(like pouring salt on a snail)
Group Translocation
a molecule is chemically modified as it crosses the plasma membrane
Endocytosis & Exocytosis only occurs in _______.
Eukaryotes
Endocytosis
the cell membrane invaginates itself to form a vacuole and bring molecules into the cell
molecules ENTER the cell
Exocytosis
a vacuole fuses with the cell membrane to release molecules outside of the cell
molecules EXIT the cell
3 Methods of Endocytosis
- Phagocytosis
- Pinocytosis
- Receptor-Mediated Endocytosis
Phagocytosis vs Pinocytosis
Phagocytosis is “cell eating”
Pinocytosis is “cell drinking”
Receptor-Mediated Endocytosis
Receptors on the surface of the plasma membrane bond to specific molecules. Once the molecule bonds to the receptor, the plasma membrane will invaginate to form a vacuole and take it in.
mono-
one
amphi-
both
perio-
around
monotrichous
one flagella
amphitrichous
one flagella at each end of the cell
(two total)
lophotrichous
multiple flagella at one end of the cell
periotrichous
multiple flagella around the cell
chemotaxis
movement of a cell in response to chemical cues
Which bacteria is a common cause of UTIs?
Escherichia coli
(E. coli)
cilia
short, hair-like projections on the surface of eukaryotic cells for movement
Endoflagella AKA
Axial Filaments
What type of cytoskeleton structure forms spirochaetes?
Axial Filaments
Two common spirochaetes causing illness?
- Treponeum padillum (causes Syphilis)
- Borrelia burgdorferi (causes Lyme disease)
Fimbriae
used for attachment to surfaces and other cells
DNA in a Eukaryote vs. DNA in a Prokaryote
Eukaryotic DNA is linear and tightly packaged in a membrane-bound nucleus
Prokaryotic DNA is circular and balled up in a nucleoid region
Histones
proteins that eukaryotic DNA is wound around to package it into a smaller space
Chromosomes
Tightly packaged DNA in Eukaryotes
HU Proteins
used to pin prokaryotic DNA together so it stays within a nucleoid region
HU Proteins are found in ______.
Prokaryotes
Histones are found in ______.
Eukaryotes
Plasmids
bonusDNA
small, circular, extrachromosomal DNA found found in bacteria
What does conjugation of bacteria allow?
Conjugation allows bacteria to share copies of their plasmids with eachother.
Are ribosomes organelles?
No
Are ribosomes found in eukaryotic cells?
Yes
Are ribosomes found in prokaryotic cells?
Yes
Ribosomes
molecules in the cells that facilitate synthesis of proteins from an RNA template
Central Dogma
DNA makes RNA makes Protein
Two types of Endoplasmic Reticulum (ER)
Smooth (SER)
Rough (RER)
ER
Endoplasmic Reticulum
The primary role of Smooth ER is:
Lipid Synthesis
The primary role of Rough ER is:
Protein Synthesis
Why is Rough ER rough?
It is embedded with ribosomes giving it a rough appearance
Golgi Complex
Packages, Sorts & Delivers Proteins
(essentially the postal service of the cell)
Lysosome
Organelle containing digestive enzymes
Chloroplasts
contain chlorophyll and use sunlight for photosynthesis to make glucose
Mitochondria
the powerhouse of the cell
makes ATP through cellular respiration
Important Parts of the Mitochondria
- Outer Membrane
- Inner Membrane
- Crista (the folds of the inner membrane)
- Matrix (the inside portion of the inner membrane)
Proposed Endosymbiotic Theory
Lynn Margulis
What is Endosymbiotic Theory?
A theory to describe the origins of mitochondria and chloroplasts
-free living prokaryotes were taken into eukaryotes and survived and over time evolved into chloroplasts and mitochondria
Proposed by Lynn Magulis (1966)
4 Pieces of Evidence spporting Endosymbiotic Theory:
Mitochondria & Chloropalts are:
1 - the same size as bacteria
2 - contains circular DNA like bacteria
3 - reproduce indepedently of host cell
4 - have prokaryotic-like ribosomes
1st Piece of Evidence Supporting Endosymbiotic Theory
mitochondria and chloroplasts are about the same size as bacteria
2nd Piece of Evidence Suuporting Endosymbiotic Theory
Mitochondria and Chloroplasts contain circular DNA
3rd Piece of Evidence Suuporting Endosymbiotic Theory
Mitochondria and Chloroplasts reproduce independently of their host cell
4th Piece of Evidence Suuporting Endosymbiotic Theory
Mitochondria and Chloroplasts have prokaryote-like ribosomes.
Mycobacterium _______ a cell wall.
has
Mycoplasma ________ a cell wall.
does not have
cocci
spherical
vibrio
comma-shaped
bacilli
rod-shaped
spirochete
spiral-shaped
diplo-
two
strepto-
chain
tetra-
4
staphylo-
grape-like cluster
sarcinae
cluser of 8
Mycoplasma pneumonia causes
walking pneumonia
mycolic acid
a waxy lipid in the cell wall of mycobacterium
Describe the Shape of a Pleomorphic Microorganism
no defined shaped because there is no cell wall to hold a set structure
Does a Gram stain work on Mycobacterium?
No.
Because the mycolic acid makes it too hard to stain
Bacterial Cell Walls Contain
Peptidoglycan
Describe how Penicillin Works
Penicillin disrupts the cross-links between strands of Peptidoglycan in the cell wall. This weakens the cell wall and causes the cell to lyse in a hypotonic environment.
Gram _______ Bacteria contains more Peptidoglycan than Gram ______ Bacteria.
Gram Positive Bacteria contains more Peptidoglycan than Gram Negative Bacteria.
LPS
Lipopolysaccharide
Lipid A is _____________.
an endotoxin
What actually happens when the Decolorizer is added to Gram Negative Bacteria?
It dissolves the outer membrane and puts holes in the peptidoglycan layer below.
L forms
bacteria that have lost their cell walls
Do Eukaryotic Cells with a Cell Wall contain Peptidoglycan?
No
Which Eukaryotic Kingdom Contains Chitin in its cell walls?
Fungi
Cellulose is found in the Cell Walls of
Plant
Some Algae
Some Fungi
Glycocalyx
a coating around the cell walls of some bacteria
3 Functions of the Glycocalyx
1) Helps Bacteria Avoid Phagocytosis by immune cells
2) Promotes Adherance #Biofilm
3) Prevents Desiccation
Which 2 Genuses of Bacteria form Endospores?
Clostridium and Bacillus
Endospores
Highly durable structures formed within the plasma membrane when a bacteria cell goes dormant due to a bad environment lacking in nutrients
Last resort for the bacteria— die or go dormant
Sporulation
the formation of an endospore
Germination
The process of an endoscope coming out of its dormant state to release a single metabolically-active bacteria
Is germination a type of reproduction?
No
