Ch 6+7 Flashcards
What devices are used to examine life at the cellular level?
light microscope, electron microscope, scanning electron microscope, and transmission electron microscope
Which microscope can study living cells in color?
light microscope
Which microscope has a very high resolution?
electron microscope
Which microscope is used for detailed study of topography?
SEM
Which microscope is used to study the internal structure of cells?
TEM
What is cytology?
the study of cell structure
What is biochemistry?
study of chemical processes of cells
What is cell fractionation?
Takes cells apart and separates major organelles and other structures
Steps of cell fractionation
homogenization (break up cell)
centrifugation (spin test tubes for separations)
Why do small cells work better than large cells?
Small cells have a greater ratio of surface area to volume. Cells need enough surface area to handle passage of enough substances to service cell. Volume grows proportionately more than surface area.
What encloses the nucleus from the cytoplasm?
nuclear envelope
What is the nuclear lamina?
lines inner membrane of nuclear envelope to maintain shape
What is the dense sphere in the nucleus and what does it contain?
Nucleolus where rRNA and subunits of ribosomes are synthesized
What is chromatin?
complex of DNA and proteins making up chromosomes
Nuclear pore
channel for substance transport between cytoplasm and nucleus
What do ribosomes do?
carry out protein synthesis
In what 2 arrays can ribosomes be found?
free: suspended in cytosol
bound: attached the ER of nuclear envelope
Components of endomembrane system?
nuclear envelope, ER, Golgi apparatus, lysosome, vacuole
What do mitochondria do?
generate ATP through cellular respiration
What do chloroplasts do?
create chemical energy through photosynthesis
What is cristae?
Folded inner membrane of mitochondria that separates it into inter membrane space and matrix, which contains enzymes and DNA and ribosomes
Proteins for cellular respirations are ______ into the inner membrane of mitochondria
embedded
What is stroma?
Fluid outside thylakoids in chloroplast
What are grana?
Stacks of thylakoids
What are thylakoids?
Flattened, interconnected sacs in the chloroplast
What is the function of a peroxisome and how does it do so?
To prevent poisoning of the cell
Removes O2 from substrates to break down and detoxify, producing H202. Simultaneously it breaks down H2O2 into water.
What are the functions of the cytoskeleton?
support, shape, motility
Microtubules
framework, tracks for movement, made of tubulin
Microfilaments
muscle contraction, changing shape, made of actin
Intermediate filaments
cell shape, anchor nucleus, made of keratin
Cell motility requires interaction of cytoskeleton with:
motor proteins
What are cilia and flagella?
microtubule-containing extensions from membrane that move fluid over surface
Structure of cilia and flagella
nine doublets of microtubules in ring and two single microtubules in center
What is a centrosome?
microtubule organizing center