4.1-4.4 Flashcards
Why do cells have a lower size limit?
If cells were any smaller, they would not be able to fit the organelles
Why do cells have an upper size limit?
Cells are the size they are bc they maximize their surface area to bring in nutrients and get rid of waste products.
What large ratio do cells need?
surface area : volume
increase in the apparent size of the object
magnification
clarity of an image
ability to see 2 close objects as separate
resolution
what are the two types of microscopes?
Light and Electron Microscopes
Which type of microscope works by passing visible light through a specimen?
light microscope
which microscope led to the discovery of the cell theory?
light microscope
what is the cell theory?
all living things are made of cells and all cells come from other cells
what is the magnification of a light microscope?
1000x
what is the resolutions of a light microscope?
0.2 micrometers
When was the light microscope first used?
in 1665 when Robert Hooke discovered cells
when were electron microscopes first used?
1950s
How are specimen viewed in an electron microscope?
They use a beam of electrons to image specimens that have been sliced thin and coated with a thin film of metal
which type of microscope has a better resolution?
electron
What are some limitations of the EM?
you can’t view living organisms and they are very expensive
What are the two types of EMs?
Scanning EM- study the detail of cell surfaces
Transmission EM- study detail of internal cell structure
In what two domains are prokaryotic cells found?
bacteria and archae
What are some features common to both types of cells?
bonded by plasma membrane
include chromosomes, ribosomes, and cytoplasm
Describe the nucleoid.
It is the region within bacteria where DNA is instead of a nucleus
visible in TEM
not bounded by a membrane
Are bacterial cells surrounded by a membrane?
yes
what is contained in the bacterial cytoplasm?
mostly water, but includes nucleoids, plasmids, ribosomes, and storage granules
What do ribosomes make?
protein
What is the relationship b//tw bacterial ribosomes and antibiotic drugs?
The antibiotics target prokaryotic ribosomes, interrupting the making of protein for the bacterium but not the healthy cells
What is the function of a capsule?
it protects the bacterial cell and serves as a barrier against white blood cells
function of pili
allow bacteria to attach to other cells
function of flagella
propels cells to move
What are the four organelles found only in plant cells?
cell wall
central vacuole
chloroplast
plasmodesmata
function of cell wall
provides and maintains shape of cells and serves as a protective barrier
function of central vacuolee
stores nutrients, waste products, and WATER
function of chloroplast
contains chlorophyl, which absorbs sunlight to use for photosynthesis
function of plasmodesmata
channel between cell walls that link plant cells together
membrane bound structures that perform specific functions in the cell
organelle
4 functional groups of organelles of eukaryotic cells
manufacturing
breakdown of molecules
energy processing
structural support, movement, and communication
What organelles are found only in animal cells?
lysosomes and centrioles
What is a phospholipid bilayer composed of?
phospholipids form a 2 layer sheet
______ face outward, exposed to H2O
______ face inward, away from H2O
hydrophilic heads
hydrophobic tails
what are attached to the surface of the phospholipid bilayer?
proteins; attached and sometimes embedded
function of nucleus
controls the cell’s activities and is responsible for inheritance
layer of complex proteins and DNA that make up chromosomes; found in nucleus
chromatin
what is copied within the nucleus prior to cell division?
DNA
function of nuclear envelope
double membrane with pores that allow material to flow in and out of the nucleus
What is the nuclear envelope attached to?
endoplasmic reticulum
function of ribosomes
to make the cell’s proteins
where are ribosomes made?
nucleolus (found in nucleus)
what are the two locations of ribosomes?
free- suspended in cytoplasm
bound- attached to the ER
manufacturing
nucleus, ribosomes, endoplasmic reticulum, and Golgi apparatus
breakdown of molecules
lysosomes, vacuoles, and peroxisomes
energy processing
mitochondria and chloroplasts
structural support, movement, and communication
cytoskeleton, plasma membrane, and cell wall
