Chapter 4: The Tour of a Cell Flashcards
Cells were discovered by
Robert Hooke in 1665
Who proposed the cell theory?
Schleiden and Schwann
Cells arise only from…
pre-existing cells
all cells represent a…
a continuous line of descent from the first living cells
limitation of cell size relies on the
diffusion of substances in and out of cells
rate of diffusion is affected by…
- surface area available
- temperature
- concentration gradient
- distance
as cell size _____ its volume _____ more rapidly than its _____ _____.
increases
increases
surface area
How can an organism have an advantage over another organism?
by being made up of many small cells
some cells overcome limitation by…
being long and skinny (ex: neurons)
Structural similarities in cells are…
- nucleoid or nucleus
- cytoplasm
- ribosomes
- plasma membrane
cytoplasm is a
semifluid matrix of organelles and cytosol
ribosomes
synthesize proteins
plasma membrane is a
selective phospholipid bilayer that allows passage of oxygen, nutrients, and waste products
prokaryotic cells
- simplest organisms
- lack a membrane-bound nucleus
- cell wall outside of plasma membrane
- contain ribosomes
- no membrane-bound organelles
The two sub-domains of prokaryotes are…
archaea and bacteria
most bacterial cells have a ____ ____ ____ composed of _____.
strong cell wall
peptidoglycan
cell walls….
- protects the cell
- maintains its shape
- prevents excessive uptake or loss of water
archaea do NOT have
a cell wall
susceptibility of bacteria to antibiotics depends on…
the structure of their cell walls
Flagella is NOT an
organelle
Flagella is a
naked thread of protein
Flagella is present in
some prokaryotic cells; sometimes more than one is present
A flagella is used for
locomotion
eukaryotic cells are…
larger than protists
eukaryotic cells have…
- internal membranes that compartmentalize their functions
- membrane-bound nucleus
- cytoskeleton
Most proteins are ____ which allows _____.
polar
membrane proteins to stay in membrane
eukaryotic cell’s genetic material is carries out by
ribosomes
what is the nucleolus?
a region where ribosomal RNA synthesis takes place
the nuclear envelope is made up of…
- 2 phospholipid bilayers
- nuclear pores
nuclear pores control
passage of molecules in and out
nuclear lamina…
- is made of strong cable-like proteins
- holds shape; supporting structure
cytoplasmic filament
filters the products that enter nucleus
fully assembled ribosomes move to
the outside of the RER
DNA combines with proteins to form
chromatin
before cell division chromatin aggregates to form
chromosomes
ribosomes are cell’s
protein synthesizing machines
ribosomes are found in…
all cell types in all three domains
ribosomal RNA (rRNA) is a
protein complex
protein synthesis also requires…
messenger RNA (mRNA) and transfer RNA (tRNA)
Ribosomes within the cell are found in
cytoplasm or associated w/ internal membranes
The endomembrane system…
regulates protein traffic and metabolic functions
the endomembrane consists of
- nuclear envelope
- endoplasmic reticulum
- Golgi apparatus
- lysosomes
- vacuoles (in plants)
- plasma membrane
vesicles..
fuse or connect endomembrane organelles via transfer; either directly or indirectly
What two organelles from the endomembrane system are NOT physically connected?
- nuclear envelope
2. endoplasmic reticulum
the rough endoplasmic reticulum is…
physically connected to the smooth endoplasmic reticulum
the rough endoplasmic reticulum is..
physically connected to the smooth endoplasmic reticulum
Three characteristics of the endomembrane are…
- its a series of membranes throughout the cytoplasm
- it divides cell into compartments where different cellular functions occur
- its a fundamental distinction between eukaryotes and prokaryotes
The endomembrane system is how…
traffic is coordinated
rough endoplasmic reticulum (RER) has ___ attached to its membrane?
ribosomes
the RER makes sure…
proteins are folded correctly
What synthesizes proteins?
ribosomes
in the RER proteins are secreted and sent to
lysosomes or the plasma membrane
the smooth endoplasmic reticulum is NOT where..
protein folding occurs
The SER functions are..
- lipid synthesis
- CA2+ storage
- detoxification
- carbohydrate metabolism
- making cell membrane for RER
the SER is a ____ ____ for ____, which is critical in reducing high _____ ______.
holding
tank
calcium
calcium concentration
The SER acting as a holding tank is critical in not having a…
high calcium concentration
the Golgi Apparatus is a…
flattened stack of interconnected membranes
golgi apparatus is made of the…
cis and trans faces
in the golgi apparatus cargo vessels travel to the…
cis face
functions of golgi apparatus is…
- clip pieces of proteins
- add sugars to proteins
- modify and sort molecules that are synthesized in one location and used at another
- uses vesicles to transport molecules to their destination
the golgi apparatus is known as the
“UPS” center
lysosomes are membrane-bound…
digestive enzymes
lysosomes arise from…
golgi and endosomes
lysosome’s enzymes…
catalyze the breakdown of macromolecules transported into the cell