Chapter 3 Cell Structure and Function Flashcards
Processes of “Life”
- growth
- reproduction
- responsiveness
- metabolism
DNA Polymerase
the enzyme used to replicate DNA
polymerase
enzyme that wants to replicate things
Transcription
process of making proteins/enzyme
- enzymes take a DNA to make a copy of messengerRNA
- mRNA starts translation (by ribosomes) to create amino acid protein peptides
size comparisons (smaller to largest)
virus
bacteria/archaea
red blood cell
eukaryotes
meters from base to nano
deci centi milli micro nano
anatomy of bacterial cells
- Glycocalyces (slime v capsule)
- Flagella
- Cell Wall
- Cell Membrane
- Cytoplasm
- Nonmembranous Organelle
- DNA
2 types of Glycocalyces
1 Capsule
2 Slime Layer
Glycocalyces
gelatinous sticky substance surrounding the outside of BACTERIAL cell
Glycocalyces composition
polysaccharides, polypeptides or both
Capsule Glycocalyces
- organized repeating units of organic chemicals
- firmly attached to cell surface
- may prevent bacteria from being recognized by its host
Slime Layer Glycocalyces
- loosely attached to cell surface
- water soluble
- sticky layer allows prokaryotes to attach to surfaces
- important for biofilms
Biofilms
- from SLIME LAYER of GLYCOCALYCES/BACTERIA
- group of microorganisms where cells stick to each other on a moist surface
- produces matriculates where they embed themselves
i. e. dental plaque, shower mold, etc
Bacterial Flagella
- responsible for mvmt
- long structures that extend beyond cell surface
- NOT present in all bacterias
Flagella Functions
- propel bacterium thru environment
- clockwise or counterclockwise rotation
- bacteria moves in response to CHEMOTAXIS (stimuli)
2 types of Chemotaxis
1 chemoattractant (run) 2 chemorepellant (tumble)
Arrangements of Bacterial Flagella
1 Atrichous 2 Monotrichous 3 Amphitrichous 4 Lophotrichous 5 Peritrichous 6 Spirochetes
Atrichous
no flagella
Monotrichous
1 flagella
Amphitrichous
2 flagellas
Lophotrichous
multiple flagellas coming out of the same pole/point
Peritrichous
flagella covers the whole cell membrane
Spirochetes
-has axial filament that acts like a corkscrew
I.e. syphillis + Lyme disease
Fimbriae
- sticky, bristle like projections
- adheres to other bacteria, hosts, +environment
- shorter than flagella
- important for BIOFILMS
Pili aka Conjugation Pilus or Sex Pilus
- special type of fimbria
- longer than fimbriae but shorter than flagella
- only 1-2 per cell
- mediates transfer of DNA from one cell to another
Conjugation
transfer of DNA from one cell to another
-a way to exchange genetic material to each other
Bacterial Cell Walls
- provides structure and shape
- protects fr osmotic forces
- composed of PEPTIDOGLYCAN
- assists in attaching to other cells
- resisting antimicrobial drugs
2 Basic Types of Bacterial Cell Wall
1 Gram Positive
2 Gram Negative
Gram Positive Bacterial Cell Wall
- relatively thick layer of peptidoglycan
- PURPLE from gram staining
- contains unique polyalcohols called teichoic acids
Gram Negative Bacterial Cell Wall
- thin layer of peptidoglycan
- addition membrane outside of peptidoglycan
- PINK from gram stain
- may be impediment to treatment of disease
main differences bw Gram Pos/Neg
- color
- thickness of peptidoglycan
- presence of outer membrane (neg only)
Cytoplasmic Membrane aka Cell Membrane
- phospholipid bilayer
- energy storage
- selectively permeable w proteins that allow substances to cross
- maintains concentration + electrical gradient
- active + passive transport of water + ions
bacterial cell membrane vs human cell membrane
- ATP in humans are made in mitochondria; in bacteria it is in cell membranes
- bacteria does NOT have as many steroids in cell membrane
Cytoplasm
- liquid portion of cytoplasm aka cytosol
- may include reserve depots of chemicals called INCLUSIONS
Endospores
- unique structures produced by Gram Positive Bacterias
- defensive strategy against unfavorable conditions
- “hibernation”
Endospore Formation
1 dna replicates and splits into original dna + forespore
2 cytoplasmic membrane grows + englufs forespore
3 dna outside of forespore disintegrates
4 correct of calcium + dipicolinic acid is deposited bw the membranes
5 spore coat forms
6 when spore coat matures, endospore is released
Nonmembranous Organelles of Bacteria
- ribosomes (site of protein synth)
- cytoskeleton (cell shape)
Anatomy of Eukaryotic Cells
- glycocalyces
- cell walls
- cytoplasmic membrane
- flegalla
- cilia
- nonmembranous organelles
Glycocalyces of Eukaryotes
- never as organized as prokaryotic capsules
- helps anchor animal cells to each other
- strengthens cell surface
- provides protection against dehydration
- cell-to-cell recognition and communication
Cell Walls of Eukaryotes
- fungi, algae, plants, + some protozoan have cell walls
- composed of polysaccharides
Polysaccharides of different Eukaryotic Cell Wall
- plant: cellulose
- fungal: cellulose, chitin, glucomannan
- algae: polysaccharides
Cytoplasmic Membrane of Eukaryotes
- phospholipids are proteins
- controls mvmt into and out of cell
- unlike prokaryotes, eukaryotes have steroid lipids
Flagella of Eukaryotes
- w/in cytoplasmic membrane
- composed of tubulin>microtubules
- filaments anchored to cell by basal body
- may be single or multiple
- does NOT rotate, but undulate rhythmically
Cilia of Eukaryotes
- shorter, more numerous than flagella
- coordinated beating mvmt
- usually used to move substances past the surface of cell
Nucleus of Eukaryotes
- often the largest organelle in cell
- contains most of cell’s DNA
- surrounded by nuclear envelope
- nucleoplasm contains chromatin
Endoplasmic Reticulum of Eukaryotes
Smooth/rough
- netlike arrangement of flattened hollow tubules
- production transport system
- larger than bacterial ribosomes
Golgi Body of Eukaryotes
- receives process, + packages large molecules for export of cell
- NOT in all eukaryotic cells
Mitochondria of Eukaryotes
- powerhouse of the cell (ATP production)
- 2 membranes composed of phospholipid bilayer
Chloroplasts
- only in cells that photosynthesize
- light harvesting structure
- have phospholipid bilayer + DNA like mitochondria
Axial Filament
Found in Spirochetes and are similar to flagella, but are located between the cell wall and an outer sheath, and are attached to one end of the organism.
