Principles of Biology Unit 5

What is the Central Dogma?

DNA --> RNA --> Protein.

What is dehydration synthesis?

The creation of larger molecules from smaller monomers where a water molecule is released.

What are hydrolysis reactions?

A chemical reaction in which a compound is broken down into smaller molecules by reacting with water.

What is catabolism?

Reactions that break molecules apart.

What is anabolism?

Reactions that build molecules.

What is metabolism?

The sum of all the homeostatic mechanisms of an organism.

What is homeostasis?

A state of balance among all the body systems needed for the body to survive and function correctly.

What is a conformer?

An isomer of a molecule that differs from another isomer by the rotation of a single bond in the molecule.

What is a resistor?

A passive electrical component that creates resistance in the flow of electric current.

Be able to define, precisely, the term adaptation.

The process by which a species becomes fitted to its environment.

What is a mutagen?

Any agents that can cause damage to DNA structure.

What is a teratogen?

Any agent that causes an abnormality following fetal exposure during pregnancy.

What is signal transduction?

The process by which a cell responds to substances outside the cell through signaling molecules found on the surface of and inside the cell.

What is tonicity?

The capability of a solution to modify the volume of cells by altering their water content.

How does osmosis differ from diffusion?

Osmosis only allows solvent molecules to move freely, but diffusion allows both solvent and solute molecules to move freely.

What is active transport?

Energy is expended to form and/or maintain a concentration gradient.

What is a vesicle?

A small bubble of membrane that has pinched off and surrounds material.

What is a transport vesicle?

Intracellular movement.

What occurs within the Golgi Apparatus?

Glycolipids and sphingomyelin.

What occurs during the process of glycosylation within the Golgi apparatus?

For the timely transport of membrane and secreted proteins.

In proteins _____ confers function?

The sequence of amino acids.

What is a genotype?

The genetic makeup of an organism.

What is a phenotype?

An individual's observable traits, such as height, eye color and blood type.

What is an allele?

One of two or more DNA sequences occurring at a particular gene locus.

What is a recessive allele/gene?

A type of allele that when present on its own will not affect the individual.

What is a dominant allele/gene?

Is always expressed, even if one copy is present.

What is/are signaling molecules?

Involved in the transmission of information from cell-to-cell and organism-to-organism.

Be able to distinguish b/n paracrine, endocrine and autocrine and how they relate to a signaling molecule.

Paracrine is short distance signal into extracellular space and communicate with adjacent cells. Endocrine is long distance signal into hormones that are released directly into the circulatory system and will impact target cells elsewhere in the body. Autocrine are cell secretes hormones that upregulates its own growth.

What is a reactive oxygen species (ROS)?

Chemically reactive molecules like H202, OH and O2- ions.

What is endocytosis?

The process where a cell engulfs fluid or particles and moves them into cytoplasm.

What is exocytosis?

The use of a vesicle to move material out of a cell.

What are plastids?

Double membrane that function in synthesis of a particular set of molecules.

How do chloroplasts, chromoplasts & leucoplasts differ?

Chloroplasts are green color plastids that are specialized for photosynthesis. Chromoplasts are different colored plastids which are responsible for distinct colors of petals and other plant parts. Leucoplasts are colorless plastids that are specialized in storing foods in plants.

What are some potential functions for chromoplasts and leucoplasts?

Chromoplast functions impart a specific color to flowers and fruits and help in pollination and dispersal of seeds. Leucoplast functions are colorless and store various food products.

Do animals possess plastids?

No.

What is a symbiotic relationship and what role does coevolution play in this relationship?

One in which organisms, people, or things exist together in a way that benefits them all. As one species changes, the other species must also change in order to adapt.

What are lysosomes?

Enzyme rich organelles that are responsible for the catabolism and breakdown of food materials, debris, captured bacteria and worn-out organelles.

What are peroxisomes?

Found in all Eukaryotic cells and do not travel to Golgi for repackaging and maturation.

What is the function of Nucleolus?

To produce and assemble the cell's ribosomes.

What is the function of the endoplasmic reticulum?

Calcium storage, protein synthesis and lipid metabolism.

Where is the endoplasmic reticulum located?

Cytoplasm.

How do the functions of the RER differ from the SER?

The SER is generally used for the creation/storage of lipids and steroids, while the RER plays a significant role in the synthesis of various proteins.

What is Primary Productivity?

The measurement of photosynthetic output or activity and measure glucose production.

How does the 10% rule relate to the 2nd law of
thermodynamics?

It states that every time energy changes form it increases entropy.

What is assimilation?

Uptake of nutrients that are released by the process of biodegradation?

What is a phylogeny?

Graphical depiction of evolutionary relationships between taxa.

What is the LUCA?

Last Universal Common Ancestor.

What is a common ancestor?

The most recent ancestral form or group from which two or more different species or groups evolved.

Review the oversimplified phylogeny of the 5 classes of vertebrates and be able to put them into some temporal order.

Fish --> Amphibians --> Reptiles --> Mammals and Birds.

What are the structural components of a cell membrane?

Lipids, proteins and carbs.

What is a phospholipid?

A type of lipid molecule that is the main component of the cell membrane.

What is a phospholipid bilayer?

Critical components of cell membranes.

What provides for the functional capacity of the cell membrane?

They require structural support to maintain shape and prevent damage to the phospholipid bilayer.

What is the modern definition of evolution?

The change in the inherited traits of a population of organisms through successive generations.

What are the four drivers of evolution?

Mutation, gene flow, genetic drift, and natural selection.

What did Dobzhansky have to say about evolution?

"Nothing in Biology Makes Sense Except in the Light of Evolution."

What is Natural Selection?

The process through which population of living organisms adapt and change.

What is Artificial Selection?

An evolutionary process in which humans consciously select for or against features in organisms.

How do the First & Second Law of Thermodynamics explain constraints on energy?

The first law states that total energy in a closed system is neither lost nor gained. The second law states that entropy constantly increases in a closed system.

What is entropy?

The measure of the disorder or loss of organization of energy.

How can we delay the onset of entropy?

Prevent the dispersion of energy.

What is potential energy?

Stored energy that depends upon the relative position of various parts of a system.

What is kinetic energy?

The energy an object has because of its motion.

What is an endergonic reaction?

Require energy input to take simple, low energy reactants and build complex, high-energy products.

What is an exergonic reaction?

Release the energy bound up in the reactants and yield simpler, low energy products.

How does endergonic and exergonic reactions relate to Anabolic and Catabolic reactions?

Catabolic reactions break down larger molecules, and this relates to endergonic because when the molecule gets broken down it releases free energy. Anabolic reactions take smaller molecules and make them bigger, and this relates to exergonic reactions because it absorbs energy.

What is an electron transport chain?

Very high concentration on the inner mitochondrial membrane that is observed in both cellular respiration and photosynthesis.

What are oxidation-reduction reactions (ReDox)?

A type of chemical reaction that involves a transfer of electrons between two species.

What is being moved between molecules or atoms in this reaction?

Atoms, ions or molecules.

What are FAD and NAD?

Coenzymes involved in reversible oxidation and reduction reactions.

What factors will influence the direction of a metabolic reaction?

The change in free energy.

Can a cell function at a chemical equilibrium?

No.

What is ATP?

Energy-carrying molecule found in the cells of all living things.

What is ATP composed of?

Sugar, phosphates and bases.

Why is ATP such an unstable molecule?

Hydrolyzes to ADP and inorganic phosphate when it is in equilibrium with water.

Why or how does ATP possess energy?

Due to the phosphate groups that link through phosphodiester bonds.

What is a phosphorylation?

A process in which a phosphate group is added to a molecule, such as a sugar or a protein.

What are the two impacts of phosphorylation?

Regulate protein activity, stability, and protein interaction and sub-cellular localization.

What is a dephosphorylation?

Reduction in the phosphorus content.

What is the focus of Cellular Respiration (CR)?

To generate usable ATP energy in order to support many other reactions in the body.

Where does CR occur?

Mitochondria and cytoplasm/cytosol.

What are the four steps of CR?

Glycolysis, Acetyl CoA, Krebs Cycle or Tricarboxylic Acid Cycle, and Electron Transport Chain (ETC).

What is glycolysis?

A process in which sugar is partially broken down by cells in enzyme reactions that do not need oxygen.

Where does glycolysis occur?

Cytoplasm.

What is the net ATP gain?

2.

What is the net ATP output of glycolysis?

34.

What happens in the Acetyl CoA formation step?

Electrons are transferred to NAD to produce NADH, which will be used by the cell to produce ATP.

What is decarboxylation?

A chemical reaction that eliminates a carboxyl group and liberates CO2.

How is decarboxylation involved in the production of Acetyl CoA from Pyruvate?

It is involved by converting pyruvate which was produced through glycolysis to acetyl CoA to be used in the Citric Acid Cycle.

Is Acetyl CoA only derived from the catabolism of carbohydrates (glucose)?

It can be produced the breakdown of carbohydrates and lipids.

What is the Krebs Cycle?

A chain of reactions through which almost all living cells produce energy in aerobic respiration.

Where does the Krebs cycle occur?

Mitochondria.

How does the Krebs cycle relate to glycolysis?

For each glucose molecule respired, the cycle reactions occur twice as two pyruvic acid molecules are formed.

What do we observe as output for the Krebs Cycle?

ATP, NADH and FADH2.

Where are the products of the Krebs Cycle going to be used?

In the inner mitochondrial membrane.

What is happening as we go from NAD --> NADH and FAD --> FADH2?

Deposits their electrons into the electron transport chain at complexes.

How does the electron transport chain (ETC) work?

Electrons are passed from one molecule to another, and energy released in these electron transfers is used to form an electrochemical gradient.

What is a proton pump?

An integral membrane protein pump that builds up a proton gradient across a biological membrane.

How are proton pumps used to produce ATP?

It binds four protons from the inner aqueous phase to make water and in addition translocate four protons across the membrane.

What is chemiosmotic phosphorylation?

A biological pathway responsible to produce ATP from an inorganic phosphate and an ADP molecule via oxidative phosphorylation.