Chapter 3- Cell Structure and Function Flashcards
Characteristics common to all living things:
Growth
Reproduction
Responsiveness
Metabolism
Are viruses a living organism and why?
No, they aren’t cells and don’t satisfy any of the characteristics that are common to all living things
Brief differences between prokaryote and eukaryote cells
Prokaryote: no nucleus, lacks membrane-bound organelles, and uses binary fission
Eukaryote: nucleus, has membrane-bound organelles, and uses mitosis
Glycocalyx
–composed of..
-function
-where is it found
-describe it
Composed of polysaccharide, polypeptide, or both
Prevents desiccation (drying out), evade phagocytosis, attachment
Found attached to the cell wall (it’s made up of a gelatinous sticky substance that forms the outermost layer of the cell exterior to the cell wall)
Glycocalyx:
If the sticky substance is ____ and ____ attached to the bacterial cell wall, the glycocalyx is described as a _____
v.s
If the sticky substance is ____ and ____ attached to the bacterial cell wall, the glycocalyx is described as a _____
Organized and firmly attached = capsule
Unorganized and loosely attached = slime layer
The cell wall gives bacterial cells a specific ___ and functions to ______ _____ from ______ ____. It also assists some cells in __________________ and contributes to resisting ______ drugs.
shape
protect destruction from osmotic forces
it assists some cells in attaching to other cells and contributes to resisting antimicrobial drugs
Mycoplasmas
Do not fit in either gram-positive or gram-negative bacteria
Lacks cell walls and has undefined shapes
The cell wall of a gram-positive bacteria forms a ____, rigid structure. It has many layers of ________, which refers to a chemical molecule that is part ___ and part _______.
thick
peptidoglycan molecules
protein
polysaccharide
Gram-positive bacteria:
The ______ part of peptidoglycan consists of long chains of repeating alternating molecules called ___ and ____. The layers are held together by ______ ________.
polysaccharide
NAG and NAM
tetrapeptide crossbridges
Gram-positive bacteria:
The peptidoglycan layer also contains teichoic acid and (1) _____ _____. What does (1)______ ___ do?
Lipoteichoic acid
It attaches the cell wall to the cell membrane
The cell walls of a gram-negative bacteria consist of a ____ ________ ___ surrounded by an outer membrane. Similar to gram-positive bacteria, they have alternating ___ and ____ structures, but they don’t have ______ _____.
Thin peptidoglycan layer
NAG and NAM
lipoteichoic acid
The outer membrane of a gram-negative bacteria is a _______. Its inner layer is composed of _____ molecules and ____.
The outer layer of the outer membrane is composed of both _____ molecules and another molecule called _____ (__)
The outer membrane of a gram-negative bacteria is a __bilayer__. Its inner layer is composed of __phospholipid___ molecules and __proteins__.
The outer layer of the outer membrane is composed of both ___phospholipid __ molecules and another molecule called __lipopolysaccharide_(LPS)
The lipid portion of LPS is known as _____ __ which is also called an ________ (this is released when the cell ____ and can cause fever, vasodilation, inflammation, shock, and blood clotting)
The lipid portion of LPS is known as LIPID A which is also called an ENDOTOXIN (this is released when the cell DIES and can cause fever, vasodilation, inflammation, shock, and blood clotting)
Why are viruses often mistaken as _______s?
Mycoplasmas
They have an undefined shape (due to no cell wall)
What’s the function of bacterial cell/cytoplasmic membranes
Maintains concentration gradient/water balance
Selectively permeable- very specifically regulates what goes in and out of the cell
3 appendages can be found on the exterior of bacterial cell walls:
Flagella, Fimbraiea, Pili
Flagella
Made up of proteins called flagellin
Used for movement
Basal body attaches hook to a cell wall and cell membrane
Flagella arrangements
Monotrichous: one
Amphiritichous: two on opposite ends
Lophotrichous: 2+ on the same end
Peritrichous: all around/surrounding
Flagella:
movement of bacteria towards or away from a particular stimulus is called ___. If the stimulus is a _____, the movement is called _______.
movement of bacteria towards or away from a particular stimulus is called TAXIS. If the stimulus is a CHEMICAL, the movement is called CHEMOTAXIS.
Types of movement for flagella
Runs (propels foward): counterclockwise
Tumbles: Clockwise
Fimbriae and pili are both used for _____ and are made up of protein molecules called ____. What’s the difference between the two?
Fimbriae and pili are both used for ATTACHMENT and are made up of protein molecules called PILINS.
Pili attachment is for a specific purpose called conjugation.
Conjugation role in pili
Pili functions to transfer DNA from one cell to another with conjugation- known as sex pili
Fimbriae vs Pili in terms of number
Fimbriae: ranges from a few to several hundred per cell
Pili: only one or two per cell
The cytoplasm of bacteria contains the DNA in a ____ ___. The main organelle consistently present is ____.
nucleoid reigion
ribosomes
Prokaryotes lack organelles, except for ____s. How are the ______s different from the ______s in eukaryotes?
Ribosomes
In prokaryotes, the size is 70S
In eukaryotes, the size is 80S
Inclusions
Found in the cytoplasm of some bacteria
May include energy deposits (polyhydroxybutrate)
Has an industrial use for recyclable plastics
Also found in the cytoplasm of some bacteria are ______ which are used as a ________ strategy against ______ _____, such as when nutrients (especially ___ and ___) are exhausted or if there isn’t sufficient _____.
Also found in the cytoplasm of some bacteria are ENDOSPORES which are used as a DEFENSE strategy against UNFAVORABLE CONDITIONS, such as when nutrients (especially Carbon and Nitrogen) are exhausted or if there isn’t sufficient MOISTURE.
Where are endospores found?
Cytoplasm
Endospores are formed by a process called _____ which takes between 8-10 ____. Endospores can remain dormant for thousands of years and when conditions become ___ for growth, endospores ___ to produce new _____ ___ (cells that _____ and ______).
Endospores are formed by a process called SPORULATION which takes between 8-10 HOURS. Endospores can remain dormant for thousands of years and when conditions become FAVORABLE for growth, endospores GERMINATE to produce new VEGETATIVE CELLS (cells that GROW and REPRODUCE).
Steps in sporulation (endospores)
1) DNA replicates
2) Cytoplasm divides, forming forespore
3) Second cell membrane forms around forespore and original DNA deteriorates
4) Peptidoglucan cortex forms between cell membranes
5) Spore coat forms around the endospore
6) Endospore gets released
Endospores are considered the _________________________ to ______. Many endospores produce toxins that can cause fatal diseases such as ____ and ____.
most difficult biological structure to destroy
anthrax and tetanus
5 comparisons between bacterial (prokaryotic) and eukaryotic cells
Bacteria:
No nucleus
Flagella rotate
Cell walls (present in most) contain peptidoglycans
Endospores are present in some
Small (70S) ribosomes
Eukaryotes:
Nucleus
Flagella undulate
Cell walls- present in plants, algae, and fungi- NO peptidoglycans
No endospores
Large (80S) ribosomes in cytosol and smaller (70S) in mitochondria/chloroplasts
In eukaryotes, the size of ribosomes is ____, except in ______ and ________ which are _____.
What theory describes what this is? Briefly describe it.
In eukaryotes, the size of ribosomes is 80S, except in mitochondria and chloroplasts which are 70S.
Endosymbiotic Theory- 2 prokaryotes: the larger anaerobic prokaryote ate the smaller aerobic prokaryote, forming a union (the eukaryote). The smaller one became an internal parasite and the larger cell became dependent on it for aerobic ATP production.
In the Endosymbiotic Theory, the _____ prokaryote evolved into ______
The aerobic prokaryote evolved into mitochondria
