CH03 - SUMMARY Flashcards
They are highly organized units containing organelles, which perform specific functions.
Cells
contains genetic material
nucleus
This is the living
material between the nucleus and the cell membrane
cytoplasm
These are the basic unit of life
Cells
Cells protect and support the body, as well as provide for cell __________, __________, and ______________.
metabolism, communication, and inheritance.
This forms the outer boundary of the cell. It determines what enters and leaves the cell.
cell membrane
The cell membrane is composed of a double layer of __________ molecules in which proteins float.
phospholipid
__________ is the movement of a solute from an area of higher concentration to an area of lower concentration within a solvent. At equilibrium, the distribution of molecules is uniform.
Diffusion
____________ is 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
_____________ pass through the cell membrane readily by dissolving in the lipid portion of the membrane. Small molecules and ions can pass through membrane channels.
Lipid-soluble molecules
This is the diffusion of water across a selectively permeable membrane.
Osmosis
In a _________ solution, cells swell (and can undergo lysis)
hypotonic
In an _______ solution, cells neither swell nor shrink
isotonic
In a _______ solution, cells shrink and undergo crenation.
hypertonic
______________ transport is the movement of a substance across a membrane by means of a carrier molecule. The substances transported tend to be large, water-soluble molecules or ions.
Carrier-mediated transport
_______________ moves substances from a higher to a lower concentration and does not require energy in the form of ATP.
Facilitated Diffusion
_________transport can move substances from a lower to a higher concentration and requires ATP.
Active transport
______________ transport uses the energy of one substance moving down its concentration gradient to move another substance across the cell membrane.
Secondary active transport
In ____________, both substances move in the same direction.
cotransport
In ___________, they move in opposite directions
countertransport.
______________ is the movement of materials into cells by the formation of a vesicle.
Endocytosis
___________ is the movement of solid material into cells.
Phagocytosis
_______________is similar to phagocytosis, except that the material ingested is much smaller and is in solution.
Pinocytosis
_____________ 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 (nucleus)
DNA and associated proteins are found inside the nucleus as __________
chromatin
__________ consist of RNA and proteins and are the sites of ribosomal subunit assembly.
Nucleoli
___________ are the sites of protein synthesis
Ribosomes
A ribosome is composed of ______________
one large and one small subunit
Rough ER is a major site of _________________
protein synthesis
Smooth ER is a major site
of ________________.
lipid synthesis
____________is a series of closely packed membrane sacs that collect, modify, 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
membrane-bound sacs containing enzymes, ____________break down phagocytized material.
Lysosomes
membrane-bound sacs containing enzymes, ____________ break down fatty acids, amino acids, and hydrogen peroxide
Peroxixomes
the major sites for the production of ATP, which cells use as an energy source. Mitochondria carry out aerobic respiration (requires O2).
Mitochondria
This supports the cytoplasm and organelles and is involved with cell movements.
Cytoskeleton
The cytoskeleton is composed of _____________, ________________, _______________.
microtubules,
microfilaments,
intermediate filaments
_________ are located in the centrosome, are made of microtubules. They facilitate chromosome movement during cell division.
Centrioles
This helps move substances over the surface of cells.
Cilia
are much longer than cilia and propel sperm cells.
Flagella
Increase the surface area of cells and thus aid in absorption.
Microvilli
During ___________, the sequence of nucleotides in DNA (a gene) determines the sequence of nucleotides in mRNA; the mRNA moves through the nuclear pores to ribosomes.
transcription
During ___________, 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.
translation
The ________ consists of a series of events that produce new cells for growth and for tissue repair.
cell cycle
The two phases of the cell cycle are __________ and __________.
interphase
cell division
DNA replicates during _____________, the nondividing phase of the cell cycle.
interphase
Cell division occurs through ___________, which is divided into four stages.
mitosis
Phase: each chromosome consists of two chromatids joined at the centromere.
Prophase
Phase: chromosomes align at the center of the cell.
Metaphase
Phase: chromatids separate at the centromere and migrate to opposite poles.
Anaphase
Phase: the two new nuclei assume their normal structure, and cell division is completed, producing two new daughter cells.
Telophase
the process by which cells develop specialized structures and functions, results from the selective activation and inactivation of DNA sections.
Differentiation
Is the programmed death of cells. This regulates the number of cells within various tissues of the body.
Apoptosis
