Biology 100 Unit 4 Flashcards
In 1665 Robert Hook found
cells
Cells are small functional units that are characterized by ___________. Living organisms are made from ____________
Living, One or more cells
Why are cells small?
So that molecules may enter and leave fast enough to meet the cells needs
How does a light microscope work?
- Light passes through the speciman
- A set of optical lenses enlarge it
_____ organisms are composed of cells
all
What is cell theory?
- all organisms are composed of cells
- all cells are composed of previously existing cells
Electron microscopes use_____________ allowing us to see up to ________ times which allows us to view ___________
a focused beam of electrons, 100,00x, intercellular structures and even viruses
A ___________ is used to look at the surface of a small object. The electron beam is reflected off of the object’s ____________________
scanning electron microscope, surface irregularities
_______________ is useful for explore the internal structure. The electron beam passes through the object and some structures slow the electrons
The transmition microscope
What are the two major types of cells
- prokryotic
- eukaryotic
who are unicellular
bacteria and protist
who are multicellular
plants and animals
What make prokaryotic cells unique
- very small
- no nucleus
- No organelles
- Independent of other cells
What make Eukaryotic cells unique
- varying sizes
- dominant nucleus
- highly structured
- contains membrane bound organelles
- Division of labor among organelles
- May form tissues
Give an example of a unicellular eukaryote
paramecium
___________ is a thin boundary separating the cell from its environment
the plasma membrane
The membranes of cells are composed of
- phospholipids
- proteins
The membrane acts as a boundary for
biochemical reactions
The membrane phospholipids are arranged in a double layer called the
phospholipid bilayer
The ___________ is the model that shows how phospholipids and protein molecules may drift through the membrane
the fluid mosaic
________ molecules can move with in this in the membrane
fluid
different types of proteins exist with the membrane
mosaic
the plasma membranes of cells are
selectively permeable
the plasma membrane controls ________ and influences which substances may cross into the cell and at what speed
energy
the control center of the cell
nucleus
Inside the nucleus DNA is present and expressed as segments called ______
genes
What genes express to ___________
produce proteins
surrounding the nucleus is another membrane called
the nuclear envelope
the nucleus stores genetic information in the form of
chromosomes
When DNA is transferred to _______ it becomes accessible
RNA
The cell has a variety of seperate membrane bound compartments called
organelles
Many organelles surrounded by membrane are part of the
endomembrane system
The endomembrane system includes
- endoplasmic reticulum
- Golgi apparatus
- Lysosomes and Vacuoles
The endoplasmic reticulum is composed of two distinct components
- rough ER
- smooth ER
what form on the membrane of the rough ER that give the ER its rough appearance
Ribosomes
the main function of the rough ER are to produce
protein precursors
new membrane molecules
The smooth ER has no ribosomes on its surface, it produces
lipids steriods, and hormones
Protein precursor molecules are packaged and transported in
vesicles
the ________ receives precursors from the Er then refines, stores, and repackages proteins so they can be sent to areas inside and outside the cell where they can function
golgi apparatus
is a type of vesicle containing digestive enzymes. They fuse vacuoles to digest food particles as well as damage organelles inside the cell
lysosomes
membrane sacs
vacuoles
the ___________ and ___________ are inter conncted membrane bound organelles linked as a protein making conyor belt
golgi and ER
What are the two types of vacuoles
vacuoles of protists and the central vacuoles of plants
Plants have membrane bound organelles called
chloroplast
chloroplast conduct
photosynethesis in plants
Both plants and animals have ___________ which conduct cellular energy processes
mitocondria
the internal network of fibers called the _________________ helps the cell maintain its shape, structure, and anchor other organelles
cytoskeleton
The cytoskelliton is made of
micro filaments, intermediate filaments, and microtubules
________ are made from an arrangment of microtubials
cilia and flagella
use whip like beats to propel a cell through an enviroment
flagella
are short types of flagella that are coordinated and provide propulsion in wavelike back and forth movements
cilia
the human windpipe is lined with
cilia which bring up polluatants
