Chapter 4 Flashcards
Cell Theory
All organisms are composed of cells, cells are the basic units of structure and functions, cells come only from preexisting cells (self-reproducing)
Surface-area-to-volume ratio
As cells increase size, surface area becomes inadequate to exchange materials (smaller size = goood)
Prokaryotic Cells
Lack membrane-bound nucleus. Located in Bacteria and Archea domains
Eukaryotic Cells
Posses a nucleus, belongs in Eukarya domain
Cell envelope
Consists of plasma membrane, the cell wall, and glycolyx
Plasma Membrane
Phospholipid bilayer embedded with proteins. Regulates entrance and exits of subtances
Mesosomes
Found in prokaryotic cells, plasma membrane can form this. Increases internal surface area
Cell Wall
maintains shape of the cells
Glycocalyx
a layer of polysaccharides. If the layer is well organized it is called a capsule. Helps bacteria attach to surfaces
Cytoplasm
A semifluid solution composed of water and inorganic and organic molecules encased by plasma membrane
Ribosomes
Prokaryotic DNA synthesized on tiny structures. Still contain RNA and protein in two subunits.
Cyanobacteria
Bacteria that is capable of photosynthesis in the same manner as plants
Thylakoids
Chlorophyll and other pigments absorb solar energy for production of carbohydrates. Third membrane of chloroplasts
External Structures of Prokaryotic
Flagella, Fimbriae, and Pili. Made up of protein
Flagella
Pushes the cell forward, like a tail
Fimbriae
Hairlike bristles that allow adhesion to surfaces
Conjugation Pili
Rigid, tubular structures used by prokaryotes to pass DNA from cell to cell
Organelles
Distingushes Eukaryotic and Prokaryotic cells, internal membrane-bound compartments
Origin of Eukaryotic Cells
First cells were prokaryotics, then evolved to be Eukaryotic.
Endosymbiotic Theory
Theory that states how Eukaryotic Cells came to be and the importance of mitochondria and chloroplasts origin
Vesicles
Membranous sacs that enclose the molecules and keep them seperate from cytoplasm
Cytoskeleton
Serves as ‘tracks’ for the vesicles. Similar to a 3D road system inside the cell
Cellulose
Found in plant cells, therefore they have a different composition from the bacteria cell wall
Nucleus
Essential to life and function of Eukaroytic cells. Contains genetic info (DNA)
Nucleoplasm
Semifluid matrix found within the interior of the nucleus
Chromatin
Combo of proteins and nucleic acids
Chromosomes
Originated from Chromatin, but they coiled into rodlike structures. Carries DNA and Genes
Nuclear Envelope
A double membrane which seperates the nucleaus and cytoplasm
Nuclear Pores
Acts as gatekeepers to regulate what goes in and out
Endomembrane System consists of
Nuclear envelope, membranes of endoplasmic reticulum, Golgi apparatus, and vesicles
Endoplasmic Reticulum (ER)
System of membranous channels and saccules. Consists of smooth ER and rough ER
Rough ER
Studded with ribosomes outside the membrane that faces cytoplasm. Can produce proteins. Form vesicles to transport
Smooth ER
Does not have attached ribosomes. Increased smooth ER helps produced more lipids. Form vesicles to transport
Golgi Apparatus
Made up of stacked, slightly curved, flattened succles. One side is directed towards ER, other side is directed towards plasma membrane. Vesicles from smooth / rough ER are received by Golgi.
Lysosomes
Vesicles produced by Golgi. Assist in digestion material in cells into subunits that are exported or recycled
Microbodies
Variety of membrane-bound vesicles within Eukaryotic cells. Contain special enzymes to preform specific functions (peroxisome)
Peroxisome
Example of a microbody, a vesicle that break down fatty acids. Assistants to other organelles. Also found in plant cells, they can carry out an opposite reaction to photosynthesis
Vacuoles
Membranous sacs that store substances. Mainly found in fat cells and are essential to plant function.
Central Vacuole
In plant cells, can take up to 90% volume in the cell. Provides structual support and helps produce more cytoplasm with increased size.
Chloroplasts
Uses solar energy to synthesize carbohydrates during photosynthesis. Has a 3 membrane system
Mitochondria
Breaks down carbohydrates products to produce ATP during cellular respiration
Stroma
A semifluid enclosed by a double membrane, found in chloroplasts.
Plastids
Plant organelles that are surrounded by a double membrane with varied functions
Mitochondira
Placed where energy is most needed. Have two membranes. Produce the most ATP
Cristae
Inner membrane of mitochondria, encloses semifluid matrix
Cytoskeleton importance
Cell shape, movement, internal transport. Contains filaments which help for shape and movement. Responds to change
Actin Filaments
thin, flexiable fibers
