Cells & Cell Physiology
Cell structure & Molecular Movements, Cells & Energy, Mitosis & Cell Reproduction, Protein synthesis
Terms in this set (85)
Every living thing is made up of cells
Basic Tenent of biology
Cells with no nucleus
lack internal cellular bodies called organelles
do not divide by mitosis
divide by mitosis
included= plants, animals, humans
(also known as cell membrane)
lies at the border of the cells
primarily made up of proteins and lipids, especially phospholipids
within the membrane, proteins carry out many functions
have a phosphorous-containing polar end and a non-polar end composed of the fatty acid chain.
Polar end= "hydrophilic"; attracted to water
Non-polar end= hydrophobic: avoids water
Phospholipids permit the plasma membrane to grow when vesicles from the golgi bodies fuse with it.
span the entire width of the membrane, protruding on both sies and serving as channels for membrane transport
may also serve as carriers of organic molecules
attach to the membrane surface
many act as enzymes, and others help to bring about changes in cell shape during division & during cellular contractions
the movement of molecules from an area of high concentration to one of lower concentration
occurs because the molecules are constantly colliding with one another, and the molecules tend to move away from where they are most concentrated.
the pathway that molecules take during difusion
diffusion of water molecules across a semiprmeable membrane from an area of low solute (water) concentration to an area of high concentration
membrane that lets only certain molecules pass through
higher concentration of solute
lower concentration of solute
assisted by proteins present in the membrane
the proteins only prmit certain molecules to pass membrane
proteins carry chemical substances across the membrane from a region of lower concentration to a region of higher concentration.
Takes place "against the gradient"
requires energy derived from adenosine triphosphate (ATP)
a small patch of plasma membrane folds in and encloses particles or tiny volumes of fluid at the cell surface. The membrane enclosure then pinches off into the cytoplasm, forming a vesicle.
Endocytosis is performed by WBC when they remove foreign microbes from the bloodstream
when endocytosis involves particulate matter
when endocytosis involves droplets of fluid
substances move from the interior of the cell to the eternal environment outside the cell.
this process is used for the secretion of hormones by endocrine cells, for the release of neurotransmitters at the tip of the nerve cell, and for the secretion of mucus by cells in various organs.
Membranous sacs migrate to the plasma membrane. Here, they fuse with the membrane, and the fused membrane ruptures, thereby spilling the contents of the sac into the external environment.
composed, primarily, of histone protein and DNA.
form a supportive framework for the 'DNA
coil with one another to form the chromosome
membranous sacs with inner partitions; site where energy released from food molecules and ATP synthesized
semifluid substance forming the foundation of the cell
little organs within the cell
series of membranes extending throughout the cytoplasm of the cell
rough endoplasmic reticulum
endoplasmic reticulum with ribosomes present
rough endoplasmic reticulum is the region where some protein synthesis ocurs in the cell
bodies where the amino acids are chemically linked together to form proteins
smooth endoplasmic reticulum
endoplasmic reticulum with no ribosomes present
The site of lipid and membrane synthesis and calcium storage
Golgi Body/ "golgi apparatus"
series of flattned sacs, usually curled at the edges.
the sacs pinch off bits of themselves to form droplike vesicles.
In the Golgi body, the cells' proteins and lipids are processed and packaged in vesicles before moving to their final destination.
contain enzymes for intracellular digestion
nonmembranous structure composed fo two rodlike centrioles.
Helps distribute chromosomes to daughter cells during cell reproduction and initiates formation of cilia
Cilia & Flagella
Hairlike projections attached to basal bodies beneath cell membrane.
Propel fluids over cellular surface and enable certain cells to move.
Membranous sacs that contain various substances being transported within the cell
Microfilaments, Intermediate filaments, and microtubules
Thin rods and tubules that provide support to cytoplasm and help move objects within the cytoplasm; make up cytoskeleton
Porous double membrane separating nuclear contents from cytoplasm that maintains shape of the nucleus and controls passage of materials between nucleus and cytoplasm
Dense, nonmembranous body composed of protein and RNA that contains materials to form ribosomes
Fibers composed of protein and DNA molecules that contain genetic information for protein synthesis
chemical reaction in which the products end up with less energy than the reactants
chemical reaction in wich energy is obtained from some source, and stored in some form
Proteins that speed up chemical reactions while themselves remaining unchanged. They lower the required amount of activation energy needed for a chemical reaction.
the substance being acted on by an enzyme
The Cell Cycle
The repetition of cellular growth and reproduction.
Generally divided into two major periods; Interphase and Mitosis
the period during which the cell performs its unique functions, also the time during which DNA replication occurs
the period during which the DNA of the nucleus of the cell is separated into two daughter cells. the actual division of the cell into two is called cytokinesis.
G1 phase (of the cell cycle)
follows mitosis, represents the time in which the cell is synthesizing its structural proteins and enzymes and growing
S phase (of the cell cycle)
synthesis of DNA, proteins, an centrioles
G2 phase (of the cell cycle)
microtubule proteins form spindle apparatus; chromatin begins condensing
Prophase (of Mitosis)
duplicated chromosomes coil, nucleus and nucleolus disappear, spindle apparatus is completed, chromosomes move to center of the cell
Metaphase (of Mitosis)
centromeres line up on metaphase plate
Anaphase (of Mitosis)
Centromeres split, chromatids move to opposite spindle poles
Telophase ( of Mitosis)
chromosomes uncoil, nucleus and nucleoli form, spindle apparatus is dismantled, cytokinesis is completed
cleavage furrow is formed by contracting microfilaments; the cell's cytoplasm is divided by cleavage
Ribosomal RNA (rRNA)
part of ribosomes.
transfer RNA (tRNA)
Molecules of tRNA exist free in the cytoplasm of cells and ferry amino acids to the ribosomes using protein synthesis
Messenger RNA (mRNA)
receives the genetic code in DNA and carries the code into the cytoplasm. The genetic info is thus transferred from the DNA molecule to the mRNA molecule, and the mRNA uses the genetic info to synthesize a protein.
synthesis of mRNA using the base sequence of DNA to determine the base sequence of mRNA
synthesis of protein using the codon sequence of mRNA to direct the amino acid sequence of the protein.
Organisms whose cells have a nucleus and organelles are known as _________
The plasma membrane of cells is composed primarily of lipids known as__________
The movement of molecules from a region of high concentration to a region of low concentration is referred to as_____________
Water molecules move across the plasma membrane from a region of low solute concentration to a region of high solute concentration in the process of___________
Facilitated diffusion takes the place in the plasma membranes with the assistance of __________
When chemical substances are moved from a region of low concentration to a region that is already high in concentration, the process is known as_____
Endocytosis can imply phagocytosis when particulate matter is taken into the cell, but when droplets of fluid are taken in, the process is known as__________
A nucleus is present in all human cells except
red blood cells
Proteins providing a supportive framework for the DNA in chromosomes are composed of __________
The dense mass within the nucleus containing ribonucleic acid is referred to as___________
When ribosomes are present on the endoplasmic reticulum, the endoplasmic reticulum is said to be___
Before being sent to their final destinations, proteins and lipids are processed in a cellular organelle called the ___________
Organelles where cell energy is released from food molecules and where ATP molecules are produced are the____________
The main components of the cytoskeleton are intermediate filaments, microfilaments and
Those chemical reactions taking place in the body and accompanied by a release of energy are known as____________
Those chemical reactions in which energy is obtained and trapped from the environment are called ________
Proteins that speed up chemical reactions while themselves remaining unchanged are__________
with a few exceptions, the names of enzymes end in________
The immediate energy currency used by virtually all cells of the human body is ___________
When the temperature increases, the rate of an enzyme reaction____________
The three parts of an ATP molecule are adenine, phosphate units, and the sugar known as _________
In the cell nucleus, DNA molecules are wound around globules of histone to yeild___________
During the time the chromosomes cannot be distinguished, the mass of DNA in the cells nucleus is called_____________
The phase of the cell cycle during which the cell divides to form two daughter cells is called________
The phase of interphase in which the DNA replicates in preparation for mitosis is_____________________
The phase of interphase when the cell synthesizes its structural proteins and enzymes__________
During the G2 phase of interphase, the cell prepares for mitosis and proteins organize themselves into a series of fibers called______________