Chapter 7 cells Flashcards
what is a cell
smallest unit of organization in the body can form functions without the aid of other cells.
What is tissue
cells with similar characteristics of form and function group together to form a tissue.
exocytosis
an active transport of material from a vesicle within the cell out into the extracellular environment occurs when there is fusion of a vesicle membrane.
endocytosis
The uptake of materials from the extracellular environment.
why do cells reproduce
cells in tissue undergo division to reproduce and replace the dead tissue cells. As a result two identical daughter cells are formed.
how cells interact with the
extracellular environment
exocytosis and endocytosis
( active transport)
phagocytosis
The engulfing and digesting of solid waste and foreign material through enzymatic breakdown.
Organelles
metabolically active specialized structures that allow each cell to function according to its genetic code.
ribosomes
produced in the nucleolus from rRNA and protein molecules and are assembled in the cytoplasm
lysosomes
produced by golgi complex they digest waste and foreign material in and around the cell.
golgi complex
takes in modified proteins from the ER for subsequent segregation,
packaging, and
transport of protein compounds
The Golgi complex was first described in 1898 by an Italian anatomist named Camillo
Golgi.
vacuoles
spaces and cavities within a cell
endoplasmic reticulum
modifies proteins for the cell
can be either smooth or rough based on the absences (smooth) or presence of ribbosomes (rough)giving them both a different outer texture and differnt functions.
mitochondria
-Most numerous in the cell
-considered the power station
-they are a major source for adosine triphosphate (ATP)
-site of many metabolic reactions
ATP
Adenosine triphosphate
centrosome
contains 2 cylinder centrioles.
always near the nucleus
forms mitotic spindles
intercellular junctions
joins cells in tissues
disc shpaed
desmosome
forms intercellular junctions
hemidesmosomes
a intercellular junction that connects a cell to a non-cellular structure (enamel of a tooth)
has tonofilaments on one side.
cytoplasm
includes the semifluid part contained within the cell membrane as well as the cytoskeleton. it contains structures and cavities
nucleus
-largest and most dense
-found in all cells except mature red blood cells
-most have a single nucleus but some are multinucleated like osteoclast.
-the main nucleic acid in the nucleoplasm is DNA in the form of chromatin.
cell membrane
surrounds the cell to keep the organelles inside. made of a phospholipid bilayer made of phospholipids and proteins
components of the cytoskeleton
microfilaments
intermediate filaments
microtubules
chromosomes
concentrations of chromatin in a dividing nucleus
microfilaments and microtubules consist of specialized
proteins
DNA in the nucleus is in the form of
chromatin
chromatin condense into
chromosomes during prohase of mitosis
centromere
clear constricted middle of two daughter chromosome
chromatids
two daughter chromosomes joined by a centromere.
in cellular division chromatin condense into
chromosomes
nucleolus
center of the nucleus
most produces r RNA and the nucleotides of the two other types of RNA
DNA contains
adenine
thymine
guanine
cytosine
nucleoplasm
contains important molecules used in the construction of ribosomes and nucleic acid.
cilia
short numerous projections
flagella
long few projections
intermediate filaments
thicker thread like microscopic structure within the cytoplasm
tonofilaments
a intermediate filaments
Interphase
DNA is replicated
cells engage in growth,metabolism,organelle replacement,substance production
prophase
chromatin condenses into chromosomes.
replicated centrioles migrate to opposite ends of the cell
nuclear membrane and nucleolus disintegrate
metaphase
chromosomes centromeres align in the middle
anaphase
centromeres split and each chromosomes separates into two chromatids
chromatids migrate to opposite ends of the poles by mitotic spindles.
telophase
The division of two daughter cells occur with nuclear membranes reappearing.
