SEELEY'S HUMAN ANATOMY AND PHYSIOLOGY 10TH EDITION - Chapter 3

is the basic living unit of all organisms also the smallest units that have all the characteristics of life.

Cell

What is an average size of an cell?

one-fifth the size of the smallest dot you can make on a sheet of paper with a sharp pencil

Each cell is a highly organized unit. Within cells, specialized structures called _____________ perform specific functions.

Organelles

The living material surrounding the nucleus is called __________, and it contains many types of organelles.

Cytoplasm

The cytoplasm is enclosed by the _________ or plasma membrane.

Cell membrane,

Contains genetic material of cell (DNA) and nucleoli; site of RNA synthesis and ribosomal subunit assembly

Nucleus

Site of protein synthesis

Ribosomes

Has many ribosomes attached; site of protein synthesis (rough ER)

Rough endoplasmic reticulum

Site of lipid synthesis; participates in detoxification (smooth ER)

Smooth endoplasmic reticulum

Modifies protein structure and packages proteins in secretory vesicles

Golgi apparatus

Contains materials produced in the cell; formed by the Golgi apparatus; secreted by exocytosis

Secretory Vesicle

Contains enzymes that digest material taken into the cell

Lysosomes

Breaks down fatty acids, amino acids, and hydrogen peroxide

Peroxisome

Site of aerobic respiration and the major site of ATP synthesis

Mitochondrian

Supports cytoplasm; assists in cell division and forms components of cilia and flagella. This are are hollow structures formed from protein subunits.

Microtubule

Facilitate the movement of chromosomes during cell division

Centrioles

Move substances over surfaces of certain cells

Cilia

Propel sperm cells

Flagella

Increase surface area of certain cells

Microvilli

Four important functions performed by our body cells

-Cell metabolism and energy use

-Synthesis of molecules

-Communication

-Reproduction and inheritance

The _______________ is the outermost component of a cell. It forms the boundary between material inside the cell and material outside it. It is is composed of a double layer of phospholipid molecules in which proteins float. The proteins function as membrane channels, carrier molecules, receptor molecules, enzymes, and structural components of the membrane.

Cell membrane, or plasma membrane

Substances outside the cell are called __________, and those inside the cell are called ____________.

Extracellular substances, intracellular substances

Studies of the arrangement of molecules in the cell membrane have given rise to a model of its structure called the ____________.

Fluid-mosaic model

Membrane _________ and carrier molecules are involved with the movement of substances through the cell membrane.

channels

_________ are part of an intercellular communication system that enables cell recognition and coordination of the activities of cells.

Receptor molecules

Cell membranes are ____________, meaning that they allow some substances, but not others, to pass into or out of the cells.

selectively permeable

A ________ is generally composed of two major parts, solutes and the solvent.

Solution

Solutes are substances dissolved in a predominant liquid or gas, which is called the _____________.

Solvent

Solutes, such as ions or molecules, tend to move from an area of higher concentration of a solute to an area of lower concentration of that same solute in solution. This process is called _________.

Diffusion

A __________ is the difference in the concentration of a solute in a solvent between two points divided by the distance between the two points.

Concentration gradient

is a toxic waste produced inside liver cells. It diffuses from those cells into the blood and is eliminated from the body by the kidneys.

Urea

_______ constantly allow ions to pass through.

Leak channels

limit the movement of ions across the membrane by opening and closing.

Gated channels

is the diffusion of water (a solvent) across a selectively permeable membrane, such as the cell membrane, from a region of higher water concentration to one of lower water concentration

Osmosis

is the force required to prevent the movement of water across a selectively permeable membrane.

Osmotic pressure

As the solution rises, its weight produces___________, which moves water out of the tube back into the distilled water surrounding the tube.

Hydrostatic pressure

A ________ has a lower concentration of solutes and a higher concentration of water relative to the cytoplasm of the cell.

Hypotonic solution

Water moves by osmosis into the cell, causing it to swell. If the cell swells enough, it can rupture, a process called ________.

lysis

When a cell is immersed in a ________ solution, the solution has a higher concentration of solutes and a lower concentration of water relative to the cytoplasm of the cell.

Hypertonic

Water moves by osmosis from the cell into the hypertonic solution, resulting in cell shrinkage, or __________.

Crenation

which are proteins within the cell membrane, are involved in _____________________, which move large, water-soluble molecules or electrically charged ions across the cell membrane.

Carrier molecules, carrier-mediated transport mechanisms

Three kinds of carrier-mediated transport:

-facilitated diffusion

-active transport

-secondary active transport.

is a carrier-mediated transport process that moves substances across the cell membrane from an area of higher concentration to an area of lower concentration of that substance.

Facilitated diffusion

is a carrier-mediated process that moves substances across the cell membrane from regions of lower concentration to those of higher concentration against a concentration gradient.

Active transport

is a genetic disorder that affects the active transport of Cl− into cells. It is is a genetic disorder that occurs at a rate of approximately 1 per 2000 births and currently affects 33,000 people in the United States.

Cystic fibrosis

involves the active transport of one substance, such as Na+, across the cell membrane, establishing a concentration gradient.

Secondary active transport

In ___________, the diffusing substance moves in the same direction as the transported substance; in ___________,the diffusing substance moves in a direction opposite to that of the transported substance.

Cotransport, countertransport

Large water-soluble molecules that cannot be transported by carrier molecules, small pieces of matter, and even whole cells can be transported across cell membranes in membrane-bound sacs called ____________.

Vesicles

_________ is the uptake of material through the cell membrane by the formation of a vesicle.

Endocytosis

When a specific substance binds to the receptor molecule, endocytosis is triggered, and the substance is transported into the cell. This process is called ______________________________.

Receptor-mediated endocytosis

The term __________ is often used for endocytosis when solid particles are ingested.

Phagocytosis

___________ is distinguished from phagocytosis in that much smaller vesicles are formed, and they contain liquid rather than solid particles.

Pinocytosis

In some cells, membrane-bound sacs called ____________ accumulate materials for release from the cell.

Secretory vesicles

The secretory vesicles move to the cell membrane, where the vesicle membrane fuses with the cell membrane, and the material in the vesicle is released from the cell. This process is called __________.

Exocytosis

The ______________ is a large organelle usually located near the center of the cell.

Nucleus

The nucleus is bounded by a __________________, which

consists of outer and inner membranes with a narrow space

between them.

Nuclear envelope

The nuclei of human cells contain 23 pairs of ___________, which consist of DNA and proteins.

Chromosomes

During most of a cell’s life, the chromosomes are loosely coiled and collectively called _________________.

Chromatin

_______________ are the organelles where proteins are produced.

Ribosomes

The __________ is a series of membranes forming sacs and tubules that extends from the outer nuclear membrane into the cytoplasm.

Endoplasmic reticulum

__________ is ER with ribosomes attached to it. A large amount of it in a cell indicates that it is synthesizing large amounts of protein for export from the cell.

Rough ER

ER without ribosomes is called ________________.

Smooth ER

The ____________, also called the Golgi complex, consists of closely packed stacks of curved, membrane-bound sacs.

Golgi apparatus

is a small, membrane-bound sac that transports or stores materials within cells.

Vesicle

___________ are membrane-bound vesicles formed from the Golgi apparatus.

Lysosomes

is caused by the inability of lysosomal enzymes to break down the carbohydrate glycogen produced in certain cells.

Pompe diseas

are a group of hereditary diseases characterized by the accumulation of large amounts of lipids in cells that lack the enzymes necessary to break down the lipids.

Lipid-storage disorders

results from a lack of lysosomal enzymes that normally break down specific lipids in nerve cells of the brain.

Tay-Sachs disease

are small, membrane-bound vesicles containing enzymes that break down fatty acids, amino acids, and hydrogen peroxide (H2O2).

Peroxisomes

are small organelles with inner and outer membranes separated by a space.

Mitochondria

The outer membranes have a smooth contour, but the inner membranes have numer￾ous folds, called _____________.

Cristae

The material within the inner membrane is the ___________ and contains enzymes and ___________________.

Mitochondrial matrix, mitochondrial DNA (mtDNA)

The ______________, like the skeleton of the body, acts as the internal framework of the cell. It consists of protein structures that support the cell, hold organelles in place, and enable the cell to change shape.

Cytoskeleton

are small fibrils formed from protein sub￾units that structurally support the cytoplasm, determining cell shape.

Microfilaments

are fibrils formed from protein subunits that are smaller in diameter than microtubules but larger in diameter than microfilaments.

Intermediate filaments

The _____________ is a specialized area of cytoplasm close to the nucleus where microtubule formation occurs. It contains two __________, which are normally oriented perpendicular to each other.

Centrosome, centrioles

project from the surface of cells. This are cylindrical structures that extend from the cell.

Cilia

__________have a structure similar to that of cilia but are much longer, and they usually occur only one per cell.

Flagella

__________ are specialized extensions of the cell membrane that are supported by microfilaments.

Microvilli

DNA contains the information that directs protein synthesis. This process is called ____________.

Gene expression

A ________ is a sequence of nucleotides that provides a chemical set of instructions for making a specific protein. You can think of a it as the “recipe” for making a protein.

Gene

The copy of the gene produced during transcription is called __________.It travels from the nucleus to the ribosomes in the cytoplasm, where the information in the copy is then used to construct a protein by means of translation.

Messenger RNA (mRNA)

Specialized molecules, called transfer _________, carry the amino acids to the ribosome.

RNAs (tRNAs)

is the first step in gene expression and it takes place in the nucleus of the cell.

Transcription

The information in mRNA is carried in groups of three nucleotides called ___________, where each codon specifies a par￾ticular amino acid.

Codons

is the synthesis of proteins based on the information in mRNA. It occurs at ribosomes.

Translation

In each tRNA there is a three-nucleotide sequence called the ________ that pairs with the codon of the mRNA.

Anticodon

An enzyme associated with the ribosome causes the formation of a _____ between the amino acids bound to the tRNAs.

Peptide bond

As the process continues, a _________ is formed. Translation ends when the ribosome reaches the stop codon on the mRNA.

Polypeptide chain

The cell cycle includes two major phases: a nondividing phase, called __________, and cell division.

Interphase

is the formation of daughter cells from a single parent cell. The new cells necessary for growth and tissue repair are formed through mitosis (discussed next), and the sex cells necessary for reproduction are formed through meiosis.

Cell division

The 46 chromosomes are the _________ number of chromosomes and are organized to form 23 pairs of chromosomes.

Diploid

1 pair is the sex chromosomes, which consist of 2 _____________ if the person is a female or an X chromosome and a ________ if the person is a male.

X chromosomes, Y chromosome

Most cells of the body, except those that give rise to sex cells, divide by ________. A parent cell divides to form two daughter cells with the same amount and type of DNA as the parent cell.

Mitosis

During _______, the chromatin condenses to form visible chromosomes.

Prophase

After interphase, each chromosome is made up of two genetically identical strands of chromatin, called _______, which are linked at one point by a specialized region called the ________.

Chromatids, centromere

In __________, the chromosomes align near the center of the cell. The movement of the chromosomes is regulated by the attached spindle fibers.

Metaphase

At the beginning of _______, the chromatids separate. When this happens, each chromatid is then called a chromosome. At this point, two identical sets of 46 chromosomes are present in the cell.

Anaphase

During __________ the chromosomes in each of the daughter cells become organized to form two separate nuclei, one in each newly formed daughter cell.

Telophase