Test 2 Flashcards
Cells are the fundamental unit of
living things
Cell Theory
All living things are composed of cells
All cells come from pre-existing cells
Most cells are
small
1 mm Cube
Surface Area, Volume, Surface Area to Volume Ratio
Surface Area - 6 sides x 1 ^2 = 6 mm ^2
Volume - 1 ^3 = 1 mm ^3
SA:Vol - 6 mm ^-1 = (6 : 1)
2 mm Cube
Surface Area, Volume, Surface Area to Volume Ratio
Surface Area - 6 sides x 2 ^2 = 26 mm ^2
Volume - 2 ^3 = 8 mm ^3
SA:Vol - 3 mm ^-1 = (3 : 1)
4 mm Cube
Surface Area, Volume, Surface Area to Volume Ratio
Surface Area - 6 sides x 4 ^2 = 96 mm ^2
Volume - 4 ^3 = 64 mm ^3
SA:Vol - 1.5 mm ^ -1 = (1.5 : 1)
Better to be _____ cells than one _____ cell
smaller; large
The cytoskeleton provides:
Cell structure
Movement
The cytoskeleton is composed of:
Protein Fibers
The cytoskeleton provides:
Cell support and shape
The cytoskeleton aids in:
Cell movement
Organelle position
Anchor cells
The cytoskeleton consists of:
Microfilaments
Intermediate Filaments
Microtubules
______ helps the cell move and determines cell shape
Microfilaments
Microfilaments are made of
ACTIN monomers
Microfilaments:
Can shorten or lengthen as more monomers attach or detach (DYNAMIC INSTABILITY)
OR
Interact with MYOSIN to help muscles contract
Microfilaments:
Can shorten or lengthen as more monomers attach or detach (DYNAMIC INSTABILITY)
OR
Interact with MYOSIN to help muscles contract
Microfilaments Summary
Made up of strands of the protein ACTIN; often interact with strands of other proteins
______________ hold organelles in place and are stable
Intermediate Filaments
Intermediate Filament composition
Tough, rope-like, and made of various fibrous proteins
Intermediate Filaments:
Stable and permanent
OR
Important in connecting cells
Intermediate Filaments:
Stable and permanent
OR
Important in connecting cells
_______ is composed of intermediate filaments
Keratin
Intermediate Filaments Summary
Made up of fibrous proteins organized into tough, rope-like assemblages that stabilize a cell’s structure and help maintain it’s shape
Microtubules form:
An internal skeleton and transportation network
Microtubule Composition
Long, hollow cylinders made of TUBULIN dimers
Microtubules can:
Shorten or lengthen as more tubulin dimers attach or detach (DYNAMIC INSTABILITY)
Microtubules Summary
Long, hollow cylinders made up of many molecules of the protein tubulin
Tubulin consists of 2 subunits, a-tubulin and b-tubulin
Microtubules form
the interior of cilia and flagella
Microtubules are important in
movement
Microtubules (“9+2”)
9 doublets of microtubules surround 2 single microtubules
Microtubules can be moved by
motor proteins
How do motor proteins move microtubules?
DYNEIN slides microtubules past each other, NEXIN stops this (causes cilia to flex)
Motor proteins, such as kinesis, can move
organelles
How do motor proteins, like kinesin, move organelles?
KINESIN “walks” organelles such as vesicles along microtubules
The Extracellular Matrix:
Provides tissue functions in animals
Orients cell movement during tissue repair and development
Collagen and Proteoglycans hold
cells together
Collagen and Proteoglycans:
Form TISSUES
Proteins in the cell membrane connect cells to the
extracellular membrane
______ connects microfilaments in the cell to the extracellular matrix
INTEGRIN
Integrin can:
detach to allow the cell to move
Cells can be connected to each other by
Cell junctions
Tight junctions connect to
microfilaments
Ex.) Bladder
Desomosomes connect to
intermediate filaments
Ex.) Skin
______ ______ allow material to pass between cells
Gap junctions
Ex.) Heart muscle