CELL STRUCTURES AND THEIR FUNCTIONS Flashcards
are highly organized units containing organelles, which perform specific functions
Cells
contains genetic material
nucleus
the living material between the nucleus and the cell membrane
cytoplasm
forms the outer boundary of the cell.
It determines what enters and leaves the cell.
cell membrane
protect and support the body, as well as provide for cell metabolism, communication, and inheritance.
Cells
are the basic unit of life
Cells
is the movement of a solute from an area of higher concentration to an area of lower concentration within a solvent.
Diffusion
function as membrane channels, carrier molecules, receptor molecules, enzymes, and structural components of the membrane.
proteins
composed of a double layer of phospholipid molecules in which proteins float.
cell membrane
the distribution of molecules is uniform
equilibrium
the diffusion of water across a selectively permeable membrane
Osmosis
the concentration of a solute at one point in a solvent minus the concentration of that solute at another point in the solvent divided by the distance between the points.
concentration gradient
can pass through membrane channels
Small molecules and ions
pass through the cell membrane readily by dissolving in the lipid portion of the membrane.
Lipid-soluble molecules
is the force required to prevent movement of water across a selectively permeable membrane.
Osmotic pressure
in ___ cells swell (and can undergo lysis);
hypotonic solution
in an ______ cells neither swell nor shrink
isotonic solution
in ______ cells shrink and undergo crenation
hypertonic solution
is the movement of a substance across a membrane by means of a carrier molecule.
Carrier-mediated transport
moves substances from a higher to a lower concentration and does not require energy in the form of ATP
Facilitated diffusion
can move substances from a lower to a higher concentration and requires ATP.
Active transport
is the movement of materials into cells by the formation of a vesicle
Endocytosis
uses the energy of une substance moving down its concentration gradient to move another substance across the cell membrane.
In cotransport, both substances move in the same direction; in countertransport, they move in opposite directions.
Secondary active transport
is the secretion of materials from cells by vesicle formation.
Exocytosis
consists of two separate membranes that
form nuclear pores at many points on the surface of the nucleus
nuclear envelope
DNA and associated proteins are found inside the nucleus as chromatin.
DNA is the hereditary material of the cell and controls cell activities.
DNA
Nucleoli consist of RNA and proteins and are the sites of ribosomal subunit assembly.
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are the sites of protein synthesis
Ribosomes
is ER with ribosomes attached. It is a major site of protein synthesis.
Rough ER
is composed of one large and one small subunit
ribosome
does not have ribosomes attached and is a major site of lipid synthesis.
Smooth ER
is a series of closely packed membrane sacs that collect, modity, package, and distribute proteins and lipids produced by the ER.
Golgi apparatus
are membrane bound sacs that carry substances. from the Golgi apparatus to the cell membrane, where the vesicle contents are released.
Secretory Vesicles
are membrane-bound sacs containing enzymes.
Lysosomes and Peroxisomes
are the major sites for the production of ATP, which cells use as an energy source.
Mitochondria
supports the cytoplasm and organelles and is involved with cell movements.
cytoskeleton
located in the centrosome, are made of microtubules.
They facilitate chromosome movement during cell division.
Centrioles
is composed of microtubules, microfilaments, and intermediate filaments
cytoskeleton
move substances over the surface of cells
Cilia
increase the surface area of cells and thus aid in absorption.
Microvilli
are much longer than cilia and propel sperm cells.
Flagella
is regulated hy enzymes (proteins), and DNA controls enzyme production.
Cell activity
the sequence of nucleotides in DNA (a gene) determines the sequence of nucleotides in mRNA; the mRNA moves through the nuclear pores to ribosomes.
During transcription
the sequence of codons in mRNA is used at ribosomes to produce proteins. Anticodons of tRNA bind to the codons of mRNA, and the amino acids carried by tRNA are joined to form a protein.
During translation
The two phases of the cell cycle are
interphase and cell division
DNA replicates during interphase, the ______
nondividing phase of the cell cycle
consists of a series of events that produce new cells. for growth and for tissue repair.
cell cycle
occurs through mitosis
Cell division
Cell division occurs through mitosis, which is divided into four stages:
- Prophase
- Metaphase
- Anaphase
- Telophase
is the programmed death of cells. Apoptosis regulates the number of cells within various tissues of the body.
Apoptosis
the process by which cells develop specialized structures and functions, results from the selective activation and inactivation of DNA sections.
Differentiation
may be due to the presence of “cellular clocks”, the function of “death genes,” DNA damage, free radicals, or mitochondrial damage.
Aging
