Unit 1. Introduction to Cell Flashcards
Decribe CELL (4)
small, membrane-enclosed units
Filled with aqueous solution of chemicals
Ability to multiply or divide
Fundamental unit of life
Cells vary enormously in _________ and _________
appearance (size)
function (chemical reactions, cellular activities)
Similarity of Cells include: (2)
- similar basic chemistry
- have genes (genetic instruction) stored in the DNA
How does genetic information flows:
from DNA to RNA (transcription);
and from RNA to protein (translation).
In 1665, he discovered cells while looking at a thin slice of cork.
Robert Hooke
Robert Hooke describe cells as ___________ and thought that cells only exist in _______ and ________
- tiny boxes or a honeycomb
- plants and fungi
In 1673, he used a handmade microscope to observe pond scum (single-celled
organisms) which he describe as ________
- Antonie van Leeuwenhoek
- animalcules
Leeuwenhoek discovered that cells are found in ______ and ______
plants and animals
During the mid 19th century, very few cell theory
advancements were made that is probably due to the widely accepted,
traditional belief in
Spontaneous Generation
Much doubt existed around
Spontaneous Generation which conclusively disproved by
Louis Pasteur
discovery of NUCLEUS, which he describe as ‘opaque spot’ in cells of epidermis of orchids.
Robert Brown
It is the random motion of particles (Brown noticed that pollen grains in water jiggled)
Brownian motion
He coined the term
“protoplasm” to describe
the contents of the cell, describe the movement cilia
and the use of microtome
Johannes Purkinje
In 1838, he concluded that all
plant parts are made of cells
Matthias
Schleiden
In 1839- he stated that all animal
tissues are composed of cells.
Theodor Schwann
He stated that every cell originated from another existing cell and demonstrated the first evidence of cell division in 1955
Rudolf Virchow
He was first to observed cells to have thin outer layer we known today as plasma membrane
Theodor Schwann
The phrase which was used by Virchow’s to explain concept of cells arising from pre-existing cells.
“Omnis cellula e cellula”
In 1940, he invented the electron microscope that enables to see the complex structure of the cell.
Vladimir Zworykin
According to the Cell Theory, all cells today represent a ______________ from the first living cells.
continuous line of descent
Cell Theory states that: (3)
- All organisms are composed of cells (Schleiden and Schwann, 1838-39)
- Cells are the smallest living things.
(Schleiden and Schwann, 1838-39) - Cells arise only from pre-existing cells.
(Virchow, 1955)
All cells have certain structures in common which are? (3)
- genetic material – in a nucleoid or nucleus
- cytoplasm – a semifluid matrix
- plasma membrane – a phospholipid bilayer
Modern Cell Theory consists of the 3 basic components of cell theory, plus 4 additional statements which are:
- The cell pass information from cell to cell during cell division using DNA.
- All cells have basically the same chemical composition and metabolic activities.
- All cells have basically the same chemical & physiological functions.(movement, digestion, etc)
- Cell activity depends on the activities of structures within the cell. (organelles, nucleus, plasma membrane)
are required to visualize
cells
Microscope
can resolve
structures that are 200nm apart
Light microscope
can resolve
structures that are 0.2nm apart
Electron microscope
2 types of cell
Prokaryotic
Eukaryotic
Region of cytoplasm where prokaryote’s genome/ DNA
is located. Usually a singular, circular
chromosome.
Nucleoid
Small extra piece of
chromosome/genetic material which is usually 5 - 100 genes
Plasmid
Location of growth,
metabolism, and replication.
Cytoplasm
Gel-like matrix of water, enzymes, nutrients, wastes, and gases and
contains cell structures.
Cytoplasm
Bacteria’s way of storing
nutrients. Staining of some aids in identification.
Granule
thought to be a feature only of eukaryotes; discovery became a major advancement in the
study of prokaryotes
Cytoskeleton
Separates the cell from its environment; has phospholipid bilayer that characterizes semi-permeability
Plasma Membrane
Region of the bilayer that is water-loving? water-fearing?
hydrophilic
hydrophobic
Prokaryotes’ Surface Appendages (4)
Flagella
Axial filament (endoflagella)
Fimbriae
Pili
Long, thin extensions
Flagella
Wind around bacteria,
causing movement in waves.
axial filament (endoflagella)
short, fine
appendages around the cell with no role in motility
Fimbriae
tubes that are longer
than fimbriae but shorter than
flagella
Pili
Most bacteria are classified according to shape. Identify the following:
a. rod-shaped
b. spherical
c. spiral with rigid cel wall (flagella)
d. spiral with flexible cel wall (axial filament)
Bacillus
Coccus
Spirillum
Spirochete
Shape: elongated coccal
form
Coccobacilli
bacilli that occur in long threads
Filamentous
bacilli with tapered ends
Fusiform
Characteristics of Prokaryotes (5)
does not have a nucleus
single-celled organisms
have few organelles
perform few functions
(Eat, Respire, Reproduce)
smaller than other cells
Is a fluid present in the cell membrane
Cytosol
Viruses are not living because they: (4)
• are not made of cells
• need a host cell to reproduce
• are very small compared to a cell
• only contain nucleic acids
Characteristics of
Eukaryotes (6/7)
has a nucleus
can be single or multicellular
have many organelles, performing
complex functions
specialized to perform specific functions
larger than prokaryotic cells
Animals, plants, fungi and protists are
made of eukaryotic cells
• Nickname: “The
Control Center”
• Function: holds the
DNA
Nucleus
Cytoplasm
consists of: (3)
CYTOSOL – liquid portion
ORGANELLES – specialized
cellular compartments
INCLUSIONS – chemical
substances
ADD’L INFO
- Glycogen (muscle & liver
cells)
- Lipid droplets (fat cells)
- Melanin granules (skin & hair
cells)
Function: Energy formation
by breaking down food to make
ATP
Mitochondria
Nickname: The Powerhouse
is the major fuel for all cell
activities that require energy
ATP - Adenosine Triphosphate
- Function: makes
proteins
• Found in all cells,
prokaryotic and
eukaryotic
• dense particles
of rRNA and
protein
Ribosome
network of rods that
support the cell
Cytoskeleton
thick rods composed of tubulin
Eg. centrioles
Microtubules
thin filaments composed of
actin
Microfilaments
tough protein fibers
Intermediate filaments
Cellular Extensions in Eukaryotes
- microvilli
- cilia
- flagella
fingerlike
projections of the plasma
membrane; increase surface area for
absorption
Microvilli
short hair-like
projections; propel substances over
surface of cell
Cilia
long hair-like
projections; propel the cell
Flagella
Nickname: “Roads”
Function: The internal delivery system of the cell
Endoplasmic Reticulum (ER)
2 types: Smooth ER and Rough ER
Rough ER has rough appearance because it has ______ that has function to _______
ribosomes
help making proteins
Function of Smooth ER
makes fats or lipids
Nickname: The shippers
Function: packages, modifies, and
transports materials to different
location inside/outside of the cell
Appearance: stack of pancakes
Golgi Apparatus
Nickname: “Clean-up Crews”
Function: to break down food into particles the rest of
the cell can use and to destroy old cells.
Lysosomes
membranous sacs of oxidase & catalase
enzymes;
detoxify alcohol & neutralize dangerous
free radicals.
Peroxisomes
Characteristics of Plant Cell
Have a cell wall and cell membranes
Have a large vacuole unlike the animal cell
which only has small vacuoles
Have mitochondria to convert sugar to usable
energy for the cell
Have a few lysosomes
Are more rectangular in shape
Have chloroplasts to carry out photosynthesis
Make sugar to store solar energy
Function: stores water
This is what makes lettuce crisp
Vacuole
Function: traps energy from the sun to produce food
for the plant cell
Green in color
Chloroplast
Function: provides
support and
protection to the
cell membrane
Found outside the
cell membrane in
plant cells
Cell wall
Animal and Plant Cells Both Have: (7)
A nucleus
Ribosomes that make protein
Rough and smooth endoplasmic reticulum
Golgi bodies
Mitochondria
Cytoplasm
Vacuoles that store food, water and waste
products.
Characteristics of Animal Cells
Can not make their own food
Have many lysosomes
Are more round shaped
Have centrioles
Use mitochondria to release energy
Have many Golgi bodies
Have more extensive cytoskeleton than plant cells
Do not have a cell wall
Do not have a large
vacuole
Do not have chloroplasts