UNCW Biology 201 Final Exam

Cyclin

Cellular protein that play an important role in regulating the cell cycle.

Genome

Consists of the complete genetic sequence of a cell.

Somatic Cells

Non-reproductive cells.

Have two sets up chromosomes making it a 'diploid' cell.

Gametes

Reproducing cells (egg and sperm)

Have only a single set of chromosomes making it a 'haploid' cell.

What are the two main phases of the cell cycle?

1. Interphase

2. Mitotic Phase (Mitosis & cytokinesis)

Mitosis

A process of nuclear division in eukaryotic cells that conserves the number of chromosomes.

-produces two daughter cells identical to parent cells. (n=46)

What are the five stages of Mitosis?

1. Prophase

2. Prometaphase

3. Metaphase

4. Anaphase

5. Telophase

Prophase

1st stage of mitosis

Chromosomes begin to condense and form a mitotic spindle.

Prometaphase and metaphase

2nd and 3rd stage of mitosis

-Microtubules (spindle fibers) attach to the kinetochore (form at centromeres of chromatids) of chromosomes

-Chromosoms align on the metaphase plate

Anaphase

4th stage of mitosis

Chromatids split of each chromosome and heads towards opposite poles of the cell

Telophase

5th stage of mitosis

-nucleus divides into two daughter nuclei

-cytokinesis has begun

Cytokinesis

The division of the cytoplasm to form two separate daughter cells after mitosis, meiosis I & meiosis II

Meiosis

-A type of cell division that occurs in two stages (Meiosis I & Meiosis II) and produces 4 daughter cells with half as many chromosomes as the parent cell

(Diploid cell to haploid cell)

-Daughter cells have half as many chromosomes as parent cells

Chromosomes

-Carry genetic information

-In nucleus of eukaryotic cells

-Consist of DNA and protein

What are three events that occur in Meiosis but not Mitosis?

1. Synapsis and crossing over in Prophase I: Homologous chromosomes connect and exchange genetic information b/w non-sister chromatids.

2. Paired homologous chromosomes (tetrads) are at metaphase plate in Meiosis, instead of individual separated chromosomes as in Mitosis

3. At anaphase 1 the homologous chromosomes separate instead of sister chromatids

Hybridization

When two organisms are crossed with contrasting characteristics

True Breeding

When the P generation always passes down a specific phenotypic trait

P Generation

Parent generation

F1 Generation

Offspring of the P generation

F2 Generation

Offspring from the F1 generation self pollinating itself

Interphase

-The period in the cell cycle when the cell is not dividing

-Chromosomes and organelles are duplicated and cell size increases

Cleavage

-Process of cytokinesis in animal cells

-Characterized by pinching of plasma membrane

What are the three phases on interphase?

1. G1 Phase

2. S Phase

3. G2 Phase

Explain the three phases of interphase

1. G1 Phase: 1st gap of cell growth

2. S Phase: Synthesis of cell cycle; DNA is replicated

3. G2 Phase: 2nd gap of cell growth phase

Centrosome

-An organelle near the nucleus of a cell that contains the centrioles

-From which spindle fibers develop in cell division

G0 Phase

Non-dividing state occupied by cells that have left the cell cycle.

Spindle Fibers

Fanlike microtubules from centrosomes that help separate chromosomes during mitosis

Pleiotropy

A gene that has multiple phenotypic effects

Describe the shape of DNA

-A "double helix", composed of two strands twisted into a ladder

-The sugar and phosphate group compose the "backbone" of the ladder and the nitrogen base composes the "steps"

base-pairing rules for DNA & RNA

DNA: A pairs with T and G pairs with C

RNA: A Pairs with U and G pairs with C

DNA

Deoxyribonucleic acid

-Contains genetic information which hold instructions to make proteins

Replication

The name of the process where DNA is copied during the cell cycle; DNA is "unzipped" and each strand is used as a template to make another copy of DNA

DNA Polymerases

A group of enzymes that bind nucleotides together during DNA replication

RNA

Ribonucleic acid

Single stranded molecule that is translated from DNA & "read" in order to make proteins

Transcription

Process where a sequence of DNA is copied into a complementary sequence of RNA (mRNA)

RNA Polymerases

Enzyme that binds nucleotides together to make a RNA molecule

mRNA

Messenger RNA, that is "read" in order to make proteins

rRNA

Ribosomal RNA, forms part of a ribosome (cell's protein factory)

tRNA

Transfer RNA, brings amino acids from the cytoplasm to the ribosome so they can be used to make proteins

Ribosome

Cellular organelle that puts amino acids together to make proteins.

"cellular factory of proteins"

What are the building blocks of proteins?

Amino acids

Translation

Process that converts mRNA to amino acids to be used to make proteins

Codon

Sequence of three nucleotides that are used to code for a particular amino acid

Start Codon

A codon that signals the start of translation

Stop Codon

A codon that signals the end of translation

Anticodon

A codon that is complimentary to an mRNA codon

Promoter

A DNA segment that allows a gene to be transcribed; helps RNA polymerase find where gene "starts"

Operator

A gene segment that can turn a gene "on" or "off"

-If a gene is "on" it can be read to make a protein

-If a gene is "off" it cannot be read to make a protein

Operon

Segment of DNA that includes the operator, the promoter and all the genes that code for a particular physical trait

Point Mutation

A mutation in a sequence of DNA where one nucleotide is substituted for another

Frameshift Mutation

A mutation where a nucleotide has either been inserted or removed from a DNA sequence

Gene duplication

Type of chromosomal mutation where chromosome has two copies of a gene

-Usually occurs when homologous chromosomes don't line up properly during crossing over

Gene translocation

Type of chromosomal mutation where a piece of one chromosome moves to another non-homologous chromosome

Mutagens

Agents in environment that cause genetic mutations

Brief description of sequence of DNA to protein

1. mRNA synthesized in nucleus from DNA

2. mRNA exits nucleus into cytoplasm and is transported to ribosome

3. mRNA is "read" in ribosome to make a protein

Triglyceride

In a fat, three fatty acids are linked to a glycerol by an ester linkage, creating a triglyceride.

Phospholipid structure

Two phospholipids & a phosphate group are attached to a glycerol.

(The two phospholipid tails are hydrophobic and the phosphate group and its attachments form a hydrophilic head)

What are the three R-groups of amino acids?

1. Nonpolar (Hydrophobic)

2. Polar (Hydrophilic)

3. Electrically charged

Amino acids are linked together by....

Peptide bonds

What is the polymer of the amino acids?

Polypeptide

-Two or more linked polypeptide chains form a macromolecule (protein)

What do R-groups determine?

The R-groups determine the sequence of the protein. The structure determines its function.

The 4 levels of a proteins structure are...

1. Primary

2. Secondary

3. Tertiary

4. Quaternary

Describe the first level of protein structure

Primary

The sequence of amino acids in a protein determined by inherited gene information

Describe the second level of protein structure

Secondary

The polypeptide backbone of the protein coils and foils and folds into either a a-helix or b-pleated sheet

Describe the third level of protein structure

Tertiary

Determined by interactions b/w R-groups

Describe the fourth level of protein structure

Quaternary

When two or more polypeptide chains form one macromolecule

Protein structure is effected by....

pH, temperature and say concentration

Nucleic Acids

DNA & RNA

Building blocks of nucleic acids

nucleotides

Gogli Apparatus

Flattened membranous sac of cisternae

-Modifies products of endoplasmic reticulum

-Sorts and transports materials into membrane transport vesicles

Lysosome

Digest macromolecules

What are the functions of a cells plasma membrane?

Selectively permeable, cell signaling and cell adhesion

Explain the importance of chromatin

DNA and proteins form chromatin in the nucleus. Chromatic condenses to form chromosomes.

What two organelles produce energy for a cell?

Mitochondria and chloroplasts

Mitochondria

-Found in all eukaryotic cells

-Smooth outer membrane and an inner membrane folded into cisternae (Inner membrane creates inter membrane space and mitochondrial matrix)

-Site of cellular respiration

Chloroplasts

-Contain green pigment, chlorophyll

-Site of photosynthesis

Plasmodesmata

Channels that perforate plant cell walls

Chloroplasts are a member of what organelle family?

Plastids

What are the different intercellular junctions?

-In plants: plasmodesmata

-In animals: tight junctions, desmosomes, and gap junctions

What is the anchor of cilia and flagella?

Basal bodies

What is the important of transport proteins?

Allow passage of hydrophilic molecules through membranes (ex. channel proteins)

Aquaporins

Channel protein that allows passage of water

Passive Transport

Diffusion of a substance across a membrane with no energy investment

Osmosis

Diffusion of water across a membrane

Tonicity

Ability of a cell to gain or lose water

Isotonic solution

no net movement of water

Solute concentration is the same as concentration inside of cell

Hypertonic Solution

Cells loses water

Solute concentration higher than concentration inside of cell

Hypotonic Solution

Cells gains water

Concentration higher inside cells that concentration of solute

Facilitated Diffusion

Passie transport of molecules aided (sped up) by proteins

Active Transport

Requires energy to move molecules against their concentration gradient

What two forces, collectively called electrochemical gradient, drive the diffusion of ions across a membrane?

1. Chemical force: the ion's concentration gradient

2. Electrical force: the effect of the membrane potential on the ion's movement

Membrane potential

The voltage difference across a membrane

(Voltage created by distribution of positive and negative ions )

Electrogenic pump

A transport protein that generates voltage across a membrane

What is the major electrogenic pump in plants? animals?

plants: proton-pump

animals: sodium-potassium pump

Describe the effect of temperature of membrane fluidity

-As temperature cools membrane goes from a fluid state to a solid state.

-As temperate warms membrane becomes more fluid

How does cholesterol act as a buffer within a membrane?

-Cholesterol prevents membranes tight packing of phospholipids at cool temperatures

-restrains movement of phospholipids at warmer temperatures

Exergonic Reactions

(spontaneous reactions)

free energy released and stability of system increases

Endergonic Reactions

(nonspontaneous reactions)

absorption of free energy, stability decreases

Substrate

The reactant that an enzyme acts on

The substrate binds to an enzyme forming a...

enzyme-substrate complex