Chapter 2 lecture Flashcards
Robert Hooke
- 1600s
- “father of microscopy”
- coined the term “cell” to describe the basic unit of life
mattias schleiden and Theodore Schwann (1830s)
all living things are composed of one or more cells
Are the following organic molecule alive?
Proteins, carbohydrates, lipids, and nucleic acids
No
cell theory
all organisms are composed of cell and cell products
- all cells come from previously existing cells
life begins with?
cells
- each cell performs all the functions necessary to sustain life
- all the cells in our bodies originate from one initial cell
ectoderm
central nervous sytem retina and lens cranial sensory ganglia and nerves pigment cells head connective tissue epidermis hair mammary glands
mesoderm
skull head, skeletal muscle skeleton dermis of skin connective tissue urogenital sytem heart blood, lymph cells spleen
endoderm
stomach colon liver pancreas urinary bladder epithelial parts of: trachea, lungs, pharynx, thyroid, intestine
phospholipids are composed of
- 2 fatty acids chain (tail = non-polar or hydrophobic)
2. a phophate group (head = polar or hydrophilic)
fluid mosaic
fluid: molecules can move freely within the membrane
mosaic: a diversity of proteins exists within the membrane
functions of membrane proteins
- attachment to cytoskeleton and extracellular matrix
- cell signaling
- enzymatic activity
- transport
- intercellular joining
- cell-cell recognition
Hierarchy of life
ecosystem -> community -> population -> organism -> organ system -> organ -> tissue -> cell -> molecule -> atom
cells come in amazing variety of sizes and shapes
morphology
in addition to morphology cells differ in
- their ability to move
- their internal organization (prokaryotic verses eukaryotic)
are all organisms composed of cells and cell products?
yes
are all of the cells within an organisms the same?
no
how many distinct cell types make up the human body
210
we all developed from?
a single cell
- a single celled human zygote formed by fertilization is smaller than a period found in your text books
- the zygote develops into a full-blown organism with 100 trillion cells organized into complex tissues and organs
difference between prokaryotic cells and eukaryotic cells
prokaryotic cells: only domains: bacteria and archea
eukaryotic cells: pant and animal kingdoms, including the fungi (multicellular molds and unicellular yeast)
what type of cells do humans have?
eukaryotic cells
prokaryotic cells
- consist of a single enclosed compartment that is surrounded by a plasma membrane
- lacks a defined nucleus
- has a relatively simple organization
where is DNA located in prokaryotic cells?
nucleoid region
bacteria
- the most numerous prokaryotes
- do not have membrane bound compartments
- have many proteins that are precisely localized in their aqueous interior or cytosol
cytosol
the fluid material contained by the plasma membrane and the cell wall
all cells are prokaryotic or eukaryotic - difference
- eukaryotic cells contain a defined membrane-bound nucleus that is absent ini prokaryotes
- nucleus segregates the cellular DNA from the rest of body
- eukaryotic organisms can be either unicellular or multicellular
The three main parts of a cell
- plasma membrane
- cytoplasm
- nucleus
plasma membrane
- defines extent of the cell
- separates the living cell from its nonliving surroundings