chapter 5-cellular biology Flashcards
what is the cell theory
1) all living things are composed of cells
2) the cell is the basic functional unit of life
3) the chemical reactions of life take place inside the cell
4) cells arise only from pre-existing cells
5) cells carry genetic information in the form of DNA. this genetic material is passed from parent cell to daughter cell
what are the 6 kingdoms
1) bacteria
2) Archaea
3) Protista
4) Fungi
5) Plantae
6) Animalia
Cell membrane function
1) encloses the cell and exhibits selective permeability
2) regulates the passage of materials into and out of the cell
3) consists of a phospholipid bilayer with proteins embedded throughout.
fluid mosaic model
- cell membrane consists of a phospholipid bilayer with proteins embedded throughout.
- The lipids and many of the proteins can move freely within the membrane
structure of phospholipid
- long, nonpolar, hydrophobic, fatty chains of carbon and hydrogen face each other
- phosphorus containing, polar, hydrophobic heads facing outwards
what kind of structures are readily permeable in the plasma membrane
- small, hydrophobic, non polar
AND - small polar
What kind of particles cross the membrane though protein channels
small charged particles
what kind of particles cross the membrane through carrier proteins
charged ions and larger charged mc
what are the dense structures in the nucleus and what occurs there
nucleolus and rRNA is synthesized
what are histones and how does DNA complex with it during DNA replication and transcription
- histones are structural proteins with DNA wound around it
- DNA replication: DNA tightly winds around the histone compacting chromatin into chromosome
- transcription: DNA unwinds itself from the histone to allow transcription to occur
what is chromatin
loose DNA
nucleoid
in prokaryotes
- contains the circular chromosomes
what is the role of ribosomes and what are they made of
- role: protein production
- 2 rRNA sequences called ribosomal subunits
in Eukaryotes where are ribosomes synthesized and function
synthesized in the nucleolus and function in cytoplasm
in prokaryotes where are ribosomes synthesized and function
synthesized and function in cytoplasm
what is the ER
is a network of membrane-enclosed spaces involved in the transport of materials throughout the cell particularly those materials designed to be secreted by the cell
role of Rough ER
contains ribosomes and plays an important roll in the production of proteins
role of Smooth ER
involved with metabolism and production of lipids
role of golgi
-Receives vesicles and their contents from the smooth ER and then modifies them (ex. glycosylation), repackages them into vesicles and distributes the to the cell surface for exocytosis
Role of mitochondria
site of aerobic respiration within the cell, responsible for the conversion of sugars, fats, and other sources of fuel into usable energy ( specifically ATP)
-Contains its own genome ( which resembles cellular bacterial chromosomes)
structure of mitochondria
- Outer membrane: fomrs barrier with the cytosol
- Inner membrane: is folded into cristae and contains enzymes for the ETC
- Intermembrane space ( between the 2 membranes
- Matrix: within the inner membrane: contains the genome
how does the mitochondria DNA divide
binary fission
where does the cells metabolic activity occur
in the cytoplasms
by what does transport within the cells cytoplasm occur
cyclosis: streaming movement within the cell
what are Vacuoles and Vesicles and their role
membrane bound sacs involved in the transport and storage of materials that are ingested secreted processed or digested by the cell
centrioles
composed of MT and are involved in spindle organization during cell division
- Not membrane bound
- Animal cells have a pair of centrioles oriented at R angles to each other that lie in a region of the cell called the centrosome
- Plant cells do not have centrioles
what is a centrosome
organizes MT and helps regulate the progression of the cell cycle
function of lysosomes
membrane bound vesicles that break down material ingested by the cell
- contain hydrolytic enzymes
An injured cell or dying cell may self-destruct by rupturing the lysosome membrane and releasing its hydrolytic enzymes called
autolysis
function of cytoskeleton
supports the cell, maintains its shape and aids in cell motility
what is the cytoskeleton composed of
MT, microfilaments, intermediate filaments
what are microtubules
- hallow rods made up of polymerized tubulin that radiate throughout the fell and provide it with support
- They provide a framework for organelle movement within the cell
what are centriole function and what are they composed of
- they direct the separation of chromosomes during cell division
- composed of MT
what are cilia and flagella
they are specialized arrangements of MT that extend from certain cells and are involved in cell memory and cytoplasmic movement