3.6 Whole-Cell Activity (+ IMAGE OCCLUSION)

proteins

A cell's characteristics are ultimately determined by the types of ________ it produces.

genetic

Those proteins are in turn determined by the _______ information in the nucleus.

amino acids

Proteins, such as transport proteins and enzymes, are composed of specific sequences of _____ _____.

DNA

Information contained in ___ within the nucleus determines which types and in what sequence amino acids are combined at ribosomes to form proteins.

division, differentation

Through cell ________ and cell ______________, the cells that make up the human body are formed.

protein synthesis

DNA influences the structural and functional characteristics of the entire organism because it directs _______ _________.

gene expression

____ __________ is the process by which information stored in the genes of DNA molecules directs the manufacture of the various proteins of our cells.

nucleotides, nucleotide strands

A DNA molecule consists of ___________ joined together to form two __________ _______

connected

The two strands are _________ and resemble a ladder that is twisted around its long axis.

genes

Sections of these DNA strands are called _____,

which are sequences of nucleotides that provide a chemical set of instructions for making specific proteins.

transcription, translation

Gene expression involves two steps-____________ and ___________.

nucleus

Transcription occurs in the _______.

messenger RNA (mRNA)

During this process, information stored in a region of the DNA is used to produce a complementary RNA molecule, called ____________________.

translation

The mRNA molecule moves to ribosomes in the cytoplasm where ___________ occurs.

polypeptide chain

During this process, the nucleotide sequence of the molecule is used to determine the composition of a ___________ _____, a precursor to a protein.

remains

DNA is too large a molecule to pass through the nuclear pores to the ribosomes and _______ in the nucleus

protein

Through transcription, the cell makes an mRNA molecule, a copy of the gene necessary to make a particular _______

ribosomes

The mRNA then travels from the nucleus to the _________ in the cytoplasm, where the information in the copy is used to construct a protein by means of translation

amino acids

The ingredients necessary to synthesize a protein are _____ _____.

transfer RNAs (tRNAs)

Specialized molecules, called ______________________, carry the amino acids to the ribosome.

structure

DNA determines the _________ of mRNA through transcription.

separate

During transcription, the double strands of a DNA segment ________.

nucleotides

DNA ___________ of the gene pair with RNA ___________ that form the mRNA.

thymine, adenine, cytosine, guanine

Each nucleotide of DNA contains one of the following organic bases: _______, _______, _______, or _______.

uracil, adenine, cytosine, guanine

Each nucleotide of mRNA contains ______, _______, _______, or _______.

template

The number and sequence of nucleotides in the DNA serve as a ________ to determine the number and sequence of nucleotides in the mRNA.

specific

DNA nucleotides pair only with ________ RNA nucleotides

enzyme

After the DNA nucleotides pair up with the RNA nucleotides, an ______ catalyzes reactions that form chemical bonds between the RNA nucleotides to form a long mRNA segment.

molecule

Once the mRNA segment has been transcribed, portions of the mRNA ________ may be removed.

decode

Protein synthesis relies on the cell's ability to "______" the information stored in the nucleotide sequence of the mRNA produced during translation.

codons

The information in mRNA is carried in groups of three nucleotides called ______

amino acid

Each codon specifies a particular _____ ____

other

Some codons do not specify a particular amino acid but perform _____ functions.

stop codon

UAA does not code for an amino acid; instead it acts as a signal to end the translation process and therefore is called a ____ _____.

translation

___________ is the synthesis of proteins based on the information in mRNA.

nuclear pores

The mRNA molecules produced by transcription pass through the _______ _____ to the ribosomes.

small, large

Ribosomes consist of _____ and _____ subunits, which combine with mRNA during translation.

tRNA, ribosomal RNA (rRNA)

In addition to the mRNA, the process of translation requires two other types of RNA: ____ and ____________________.

one

There is ___ type of tRNA for each mRNA codon.

anticodon

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

amino acid

A specific _____ ____ is bound to another part of the tRNA.

binds

During translation, a ribosome _____ to an mRNA.

aligns

The ribosome ______ the mRNA with tRNA molecules so that the anticodons of tRNA can pair with the appropriate codons on the mRNA

peptide bond

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

codon

The ribosome moves down the mRNA one _____ at a time, releasing one of the tRNA and allowing the next tRNA to move into position.

polypeptide chain

As the process continues, a ___________ _____ is formed.

stop codon

Translation ends when the ribosome reaches the ____ _____ on the mRNA.

three-dimensional

The polypeptide chain is released and becomes folded to form the _________________ structure of the protein molecule

single, two or more

A protein can consist of a ______ polypeptide chain or ___ __ ____ polypeptide chains that are joined after each chain is produced on a separate ribosome.

increase

During growth and development, cell division allows for a dramatic ________ in cell number after fertilization of an oocyte

interphase, cell division

The cell cycle includes two major phases: __________ (a nondividing phase) and ____ ________

normal

A cell spends most of its life cycle in interphase performing its ______ functions

G1, S, G2

Interphase is divided into three phases: _ phase, phase, and __ phase

G1

In the __ phase, the cell carries out normal metabolic activity

S

In the _ phase, DNA is replicated

G2

In the __ phase, the cell prepares to divide

two

At the end of interphase, a cell has ___ complete sets of genetic material.

chromatin

The DNA is dispersed throughout the nucleus as thin threads called _________

cell division

____ ________ is the formation of daughter cells from a single parent cell

mitosis, meiosis

The new cells necessary for growth and tissue repair are formed through _______, and the reproductive cells are formed through _______.

diploid

Each of our body cells, except for reproductive cells, contains the _______ number of chromosomes

46

The _______ number of chromosomes for humans is __

haploid

Reproductive cells have the _______ number of chromosomes, which is half the diploid number of chromosomes

23

The 46 chromosomes are organized to form __ pairs of chromosomes.

sex

Of the 23 pairs, 1 pair is the ___ chromosomes

X

The sex chromosomes consist of 2 _ chromosomes if the person is female

X, Y

The sex chromosomes consist of 1 _ chromosome and 1 _ chromosome if the person is male

autosomes

The remaining 22 pairs of chromosomes are called _________

mitosis

Most cells of the body, except those that give rise to reproductive cells, divide by _______

same

During mitosis, a parent cell divides to form two daughter cells with the ____ amount and type of DNA as the parent cell.

prophase, metaphase, anaphase, telophase

Mitosis is divided into four stages: (1) ________, (2) _________, (3) ________, and (4) _________.

chromosomes

The two daughter cells produced by mitosis obtain the same number and type of ___________ as the parent cell

chromatids

Each chromosome is composed of two genetically identical strands of chromatin, called __________

centromere

The chromatids are linked by a specialized region called the __________

interphase

During __________, DNA exists as thin threads of chromatin.

replicated

During the S phase of interphase, DNA molecules are __________.

prophase

During ________ the chromatin condenses to form visible chromosomes each composed of the two chromatids as described above.

spindle fibers

Also during prophase, microtubules called _______ ______ extend from the centrioles.

centromeres

Some of these spindle fibers attach to the ___________ of each chromosome

divide, migrate

The centrioles ______ and _______ to each pole of the cell.

nucleolus, nuclear envelope

In late prophase, the _________ and _______ ________ disappear.

metaphase

In _________ the chromosomes align near the center of the cell.

regulated

The movement of the chromosomes is _________ by the attached spindle fibers.

anaphase

At the beginning of ________ the chromatids separate.

chromosome

When this happens, each chromatid is then called a __________

centriole

Each of the two sets of 46 chromosomes is moved by the spindle fibers toward the _________ at one of the poles of the cell.

divide

At the end of anaphase each set of chromosomes has reached an opposite pole of the cell, and the cytoplasm begins to ______.

telophase

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

unravel

The chromosomes begin to _______ and resemble the genetic material during interphase.

two

Following telophase, cytokinesis, or cytoplasm division, is completed, and ___ separate daughter cells are produced

tumor

A _____ is any abnormal mass of tissue that occurs within the body, usually involving cell proliferation.

malignant, benign

Tumors can either be _________ or ______

benign

______ tumors are not inclined to spread, but they may increase in size.

compress

As a benign tumor enlarges, it can ________ surrounding tissues and impair their functions.

metastasis

Malignant tumors can spread by local growth and expansion or by __________

lymphatic system, blood vessels

Metastasis occurs when tumor cells separate from the main tumor and are carried by the _________ ______ or _____ _______ to a new site, where a second tumor forms.

cancer

______ refers to a malignant, spreading tumor and the illness that results from it.

growth, differentiation

Cancer results when a

cell or group of cells breaks away from the normal control of ______ and ______________.