Chapter 4 Cell Structure and Function Flashcards
(40 cards)
Most cells are much smaller than one _____________
millimeter
-some are as small as one micrometer
______ _________ states all organisms are composed of cells and that cells come only from preexisting cells.
Cell theory
Everything that enters or leaves the cell must cross the _______ ____________ that forms the cell surface
plasma membrane
The smaller the cell the larger the ________ of the surface are to volume
ratio
Small cells are likely to have an adequate ________ ____ for exchanging wastes and nutrients.
surface area
All cells have
- plasma membrane
- nuclear region
- cytoplasm
Organelle
-membrane bound sub cellular structures found only in eukaryotes
prokaryotic cells
- lack a membrane-bounded nucleus
- structurally simple
- can be divided into two domains
- Bacteria
- Archaea
Cell envelopes
-includes plasma membrane, cell wall, and glycocalyx
capsule-well organized compact layer
slime layer-diffuse layer
Plasma membrane may fold in to form internal pouches (_________)
mesosomes
-not a true membrane-bound organelle
Cytoplasm
-semifluid solution encapsulated by plasma membrane
(water, proteins, dissolved salts, ribosomes, etc)
inclusion bodies-stored granules of various substances
Appendages
flagella-
-rotating filament for locomotion
Fimbriae
-small bristles used to attache to surfaces
Sex Pili
-hollow tube used in exchange of genetic material with other cells
Organelles of ______________ _________ communicate with one another
endomembrane system
Nucleus
- contains chromatin (uncondensed DNA & protein) in semifluid nucleoplasm.
- separated from cytoplasm by double-membrane nuclear envelope
- nuclear pores permit passage in and out of the nucleus
nucleolus
-site of manufacture of ribosomes, move to cytoplasm
ribosomes
- make proteins from instructions coded in the DNA of the chromosomes
- RNA and proteins
Ribosomes are composed of large and small subunits that serve in ______ ________
protein synthesis
Endomembrane system consists of nuclear envelope, membranes of endoplasmic reticulum, Golgi apparatus, and several types of ________
vesicles
Endoplasmic Reticulum
- produces enormous variety of molecules for the cell
- Rough E.R-studded with ribosomes
- Smooth E.R-no ribosomes
Rough E.R
- makes proteins and other substances
- makes new plasma membrane
Smooth E.R
-makes lipids, including steroids
molecules may leave the ER in transport vesicles, which bud off from the membrane of the ER
Golgi Apparatus
- consists of flattened, curved saccules
- works in partnership with the ER
- Refines, stores, and distributes the products of cells