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