Chapter 4, General Features of Cells Flashcards
The Cell Theory (3 parts)
1.) Cells are fundamental unit of life
2.) All organisms are composed of cells
3.) All cells come from preexisting cells
As cell _________ in volume, the surface area _________
increase, increases
The surface area increases at a _________ rate
lower
The cell’s volume determines its…
metabolic activities
The cell’s surface area determines its…
rate of transport into and out of the cell
As the cell grows, the metabolic activity…causing the cell to…
increases at a faster rate than surface area, so it must split to keep things balanced
Magnification…
makes something larger
Resolution…
makes something clearer
minimum distance between two objects
ability to observe 2 objects as distinct
Microscopes increase both…
magnification and resolution
Light Microscope
- 430 x
- resolving power: 200 nm
- uses light passing through the sample to observe objects
Transmission Electron Microscope
- 50 million x
- resolving power = 0.2 nm
- uses electron beam passing through sample to view objects
- cell must be killed and stained with heavy metals to block/scatter electron beam, those that pass through are focused
Scanning Electron Microscope
- 2 million x
- resolving power = 0.5 nm
- Coats surface of sample with heavy metal stains, uses electron beam to scan surface
- obtains more 3D view of object
Domains containing Prokaryotic cells…
Bacteria, Archaea
Prokaryotic cells…(3)
- lack membrane-bound organelles (nucleus)
- relatively simple
- generally smaller
Prokaryotic Cells contain…
plasma membrane
cell wall
capsule
nucleoid
cytoplasm
ribosomes
flagella
Plasma Membrane (structure and function)
single membrane, regulate transport
Cell Wall (structure and function)
Peptidoglycan membrane, protection/support
Capsule (structure and function)
Polysaccharides, prection/hydration
Nucleoid (structure and function)
aqueous, hereditary/DNA
Cytoplasm (structure and function)
aqueous, biochemical reactions
Ribosomes (structure and function)
solid - RNA and proteins, protein synthesis
Flagella (structure and function)
solid - proteins, movement
Domains containing Eukaryotic Cells
Protista, Plantae, Animalia, Fungi
Eukaryotic cells…
- contain membrane bound organelles
- are complex with many organelles
- are larger in size
Cytoplasm is _______ mixture
aqueous
Cytoplasm contain many…
proteins
Many protein are…
enzymes
Enzymes control…
a host of reactions
Reactions in cytoplasm are often…
the first reactions in important metabolic pathways
The cytoskeleton is made up of…
series of fibrous organelles
The purpose of cytoskeleton is to…
provide internal skeleton to cells
Three types of fibers that make up cytoskeleton constructed from
many protein monomers
Microtubules made up of
Tubulin
Microtubules are
largest long hollow tubes contributing to cytoskeleton
Microtubules have two different
charged ends
_________ and _________ help microtubules grow and shrink
Centrioles and Basal Bodies
Function of microtubules are to…
form cellular roads which vesicles and chromosomes move using molecular motors
Molecular motors in microtubules are…
Kinesin
Motor protein travels along microtubule from ___ end to ____ end
negative to positive
Microtubules form _____ and _____ for cellular locomotion
cilia, flagella
Microtubules form the ______ ________
Miotic Spindle
The miotic spindle …
moves chromosomes during nuclear division (mitosis)
Intermediate filaments are made of…
thing rods of keratin
There are ________ different types of intermediate filaments
over 50
Intermediate filaments do not have
charged ends
Intermediate filaments are more ____ than any other element of cytoskeleton
stable
Functions of intermediate filament (3)
- maintain cellular shape
- provide mechanical strength
- line inside of nuclear membrane to anchor nuclear pores
Microfilaments are the _____ of the three in the cytoskeleton
smallest
Microfilaments made out of
thin rods of actin
Microfilaments can exist as…
single filaments
in bundles
in networks
Functions of microfilaments (4)…
- cellular movement (muscle contraction, cytoplasmic streaming, pseudopod formation)
- cytoplasmic division (cytokinesis) to divide cell into two daughter cells following mitosis and meiosis
- occur near plasma membrane and anchor other proteins
- support plasma membrane and provide shape and strength to cell
All provide shape and strength to cell, but _______ most important
intermediate filaments
The nucleus is a ____ ______ structure
double membrane (lipid bilayer)
Function of nucleus is to …
store DNA
Nuclear membrane has thousands of nuclear pores which…
regulate transport between nucleus and cytoplasm
Pores are surrounded by complex of…
8 large protein granules
Proteins targeted for nucleus have a short peptide _________ _________ ________
Nuclear Localization Signal
Nucleolus consists of…
genes which code for ribosomal RNA
rRNAs are needed for …
Ribosome contruction
_______ have no membrane so technically are not organelle
ribosome
Function of ribosomes
proteins synthesis
Location of ribosomes (3)
- floating in cytoplasm
- attached to ER
- inside mitochondria/cytoplasm
Endomembrane system
group of functionally interrelated organelles
Endomembrane consists of (8)
nuclear envelope, ER, golgi apparatus, lysosomes, peroxisomes, vacuoles, plasma membrane, vesicles which shutter material between these
Endoplasmic Reticulum composed of…
single membrane surrounded by central lumen
ER consists of ____ and ____ sacs
folds, flattened
ER composes ____% of cell’s total volume
10
Because of ER’s _____, many times greater than Plasma Membrane
folds
The lumen is the…
hollow part of ER
Rough ER has…
ribosomes throughout