AP biology review 8-11 (copy)

What are the different forms of energy

kinetic energy potential energy and chemical energy

biological exapmle of kinetic energy

an animal running towards his next meal,

kinetic energy

the energy an object has because of its motion.

potential energy

the amount of energy something posseses due to location

chemical energy

energy stored in the bonds of atoms and molecules

biological example of potential energy

energy stored in chemical bonds, food molecules, and glycogen.

biological example of chemical energy

biomass, batteries, natural gas, petroleum, and coa

1st law of thermodynamics

energy can be transformed or transfered byt it cannot be created or destroyed

2nd law of thermodynamics

Every energy transfer or transformation increses entropy

how does photosynthesis relate to the laws of thermodynamics

energy cannot be created or destroyed, only transformed. This can be demonstrated within a classic food web where light energy from the sun is harnessed as radiant energy by plants, converted into chemical energy, and stored as complex carbohydrates.

how does cellular respiration relate to the laws of thermodynamics

during cellular respiration, some energy is lost as heat, which increases the entropy of the universe. Therefore, cellular respiration follows the laws of thermodynamics.

How do cells offset or temporarily postpone the effects of the 2nd law of thermodynamics?

Use anabolic reactions to use more energy that is being created by catabolic processes in order to move away from the tendecy of disorder

what is metabolism

the process used to store or release energy for use in the cell.

what is a reactant in a chemical reaction

the starting materials in a reaction that undergo a chemical change to form a product.

what is a product in a chemical reaction

a substance that is present at the end of a chemical reaction.

What is Gibbs free energy

the available energy of a substance that can be used in a chemical transformation or reaction.

What does it mean when Gibbs free energy is negative

the reaction will occur spontaneously.

What does it mean when Gibbs free energy is positive

the reaction is nonspontaneous

What is an exergonic reaction

When energy is lost to an enviorment

what is an endogenic reaction

Whe energy is gained during a reaction

How are endogenic and exogonic reaction related

A coupled reactions is a reaction that uses energy from an exergonic reaction to fuel an endergonic reaction.

What does ATP stand for

Adenosine triphosphate

What is the structure of ATP

an adenine nucleoside 'base', a five-carbon sugar (ribose), and triphosphate

What are the subunits from which ATP is made

a nitrogen base (adenine) and a sugar molecule (ribose),

Is this and endo or exogonic profile diagram

endogonic

Is this and endo or exogonic profile diagram

exogonic

What is a coupled reaction

Two (or more) reactions may be combined such that a spontaneous reaction may be made 'drive' an nonspontaneous one

What is a biological example of a coupled reaction

a transmembrane ion pump

What is a metabolic pathway

transforms matter and energy. Its direction is driven by reactions that are displaced far from equilibrium.

What is an enzyme

a biological catalyst that is usually a protein but could be RNA. The point is to increase the speed with which a reaction happens.

what is a substrate

the substance on which an enzyme acts.

What is a functuion of an enzyme

to increase the speed of a reaction

What happens to an enzyme during a chemical reaction

increase the rate of chemical reactions without themselves being consumed or permanently altered by the reaction.

What factors can affect enzyme catalyzed reactions

temperature, pH, and concentration.

what is phosphorlation

the attachment of a phosphate group to a molecule or an ion.

why would it be important to control enzyme catalyzed reactions

it allows each reaction to be controlled by the cell. an the speed at which each reaction is hapining

How do cells go about controlling the enzyme catalyzed reactions

through enzymes

What is catabolism

the breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism.

What is anabolism

1. the synthesis of complex molecules in living organisms from simpler ones together with the storage of energy; constructive metabolism.

The series of steps by which a signal on a cells surface is converted into a specific cellular response is called the

signal transduction pathway

Are the general aspects of cell signaling pathways similar in various organisms? What is the basis for your yes or no answer?

Yes. Those in yeast and mammals are strikingly similar and there are other similarities between signaling systems in plants and bacteria.

What two types of Local Signaling in multicellular animals are described in your textbook?

Paracrine signaling and Synaptic signaling

Plants and animals use this type of signaling for signaling at greater distances and over a diffuse area.

Hormonal Signaling (Endocrine Signaling)

What System in an animal's body transports hormones?

Circulatory System

How can cells communicate when they are in direct contact with one another?

Gap Junctions in animal cells

Plasmodesmata in plant cells

Interaction of cell surface molecules (glycoproteins) in cell-cell recognition

What are the three stages of the cell signaling process?

Reception - Transduction - Response

Define the term Ligand

A small molecule that specifically binds to a generally larger molecule

Name the three main types of membrane bound receptors.

G - protein-linked receptors, Tyrosine-kinase receptors, and ligand-gated ion-channel receptors

What is the molecular structure of all G-protein linked receptors?

Single polypeptide chain that threads back and forth 7 times through lipid bilayer of plasma membrane

Write a sequence of steps whereby a signal molecule binding to a G-protein receptor can cause an intracellular response.

- signal molecule binds to cell membrane receptor
- receptor binds inactive G-protein and causes GTP to replace GDP on protein thereby activating G-protein
- activated G-protein binds another protein (usually an enzyme) and alters the activity of the enzyme
- get cell response

What is the structure of a Tyrosine-kinase receptor?

Each polypeptide has an intracellular tail containing a number of tyrosine amino acids, and a single alpha-helix in the cell membrane.

How is a Tyrosine-kinase receptor activated?

When the signal binds to the receptor two receptor polypeptides aggregate forming a dimer, this aggregation activates the tyrosine-kinase parts of both polypeptides and these phosphorylate the tyrosines on the tail of the other polypeptide.

What does a Tyrosine-kinase receptor do once it is activated?

Inactive proteins within the cell bind to the phosphorylated tyrosine residues, the phosphate is transferred to the proteins, and the proteins become active.

What is a ligand-gated ion channel?

Protein pores in the membrane that open or close in response to a chemical signal, allowing or blocking the flow of specific ions, such as Na+ or Cl-

Are all receptors located on the cell membrane? Explain your answer and if no, indicte which molecules may interact with these non-membrane receptors.

No, some are proteins located in the cytoplasm or the nucleus of the cell. Ones that are small enough to pass between membrane phospholipids or ones that are lipid soluable.

What two sex hormones does your book indicate bind to receptors located in the cytoplasm or nucleus?

Testosterone and Estrogen

When testosterone binds to a receptor in the cytoplasm the complex goes into the nucleus of the cell and turns on

genes

Special proteins that control which genes are turned on are called

transcription factors

What action is a widespread mechanism for regulating protein activity?

phosphorylation of proteins

What is a Protein Kinase and why are they important?

A molecule that transfers phosphate groups from ATP to proteins. Many of the molecules in signal-transduction pathways are protein kinases.

What is a "phosphorylation cascade"?

A series of different molecules in a pathway phosphorylated in each turn, each molecule adding a phosphate group to the next

What are Second Messangers?

These are small, nonprotein, water-soluble molecules that are components of the signal-transduction pathway.

Why can second messengers spread rapidly throughout the cell?

Because they are small and water-soluble.

What types of signaling pathways use second messengers?

G-protein-linked receptors and tyrosine-kinase receptors

What are the 2 most common second messengers?

Cyclic-AMP and Calcium ions

What is the immediate effect of cyclic-AMP once it is produced?

Cyclic-AMP activates protein kinase A. This activated protein kinase then activates other proteins within the cell depending upon the cell type.

What role does the second messenger cyclic-AMP play in the disease Cholera?

Bacteria obtained from contaminated water gets into our intestine. A protein produced by the bacteria modifies the G-protein so that the G-protein does not function properly. Salt and water exit the cells into the lumen of the digestive tract and this material is lost from the body in profuse diarrhea.

Calcium is used as a second messenger in these signaling pathways.

G-protein-linked pathways and tyrosine-kinase pathways.

Describe the pathways that can lead to the release of calcium from the endoplasmic reticulum.

- signal molecule binds to membrane receptor
- G-protein is activated
- Phospholipase C enzyme converts a membrane lipid into DAG (diacylglycerol) and IP3 (inositol triphosphate)
- IP3 binds to ion-gated protein in ER membrane, which allows release of Calcium ions from the ER.
- Calcium ions interact with proteins to activate them

How could a signaling pathway be involved in activating genes on the chromosomes?

Special proteins within the nucleus called Transcription Factors can be phosphorylated (activated) by protein kinases. The Transcription Factor can then bind to a specific region of the DNA and initiate the process of mRNA production from the DNA strand.

What is Signal Amplification?

At each catalytic step the number of activated products is much greater than in the preceding step. The amplification effect depends on the fact that these proteins persist in active form long enough o process numerous molecules of substrate before they become inactive again.

What determines the specificity of a particular cell for a specific cellular response?

Different kinds of cell have different collections of proteins.
- signal proteins
- relay proteins
- proteins needed to carry out the response

What is step 1 of the signal transduction pathway

Recive

What happens in the first step of the signal transduction pathway

signaling molecule binds to recptor protein on target cell

Receptor protein must be complementary to

ligand

What is the signal transduction pathway doing

mechinism linking a mechanical or chemical stimuls to a specific cellular response

Is cellular respiration catabolic or anabolic

catabolic

what allows an organic molecules to posses potential energy

chemical energy through bonds

Where is the potential energy stored in organic molecules

the bonds

How is energy stored in chemical bonds released

hydrolisis

What molecule helps with the the breaking of chemical bonds?

H2O

What part of cellular respiration is anaerobic

glycolisis

What part of cellula respiration is aerobic

the Krebs cycle, and oxidative phosphorylation.

What is the principle of redox reactions

the transfer of electrons between chemical species

How is cellular respiration a series of redox reactions

glucose molecules are oxidized and oxygen molecules are reduced to generate water molecules.

What is being oxidized in cellular respiration

glucose

What is being reduced in celllar respiration

oxygen

what is the importance of NAD+ in cellular respiration

is the electron acceptor

What is gylcolisis

a series of reactions that extract energy from glucose by splitting it into two three-carbon molecules called pyruvates.

Where does glycolisis occur in the cell

in the cytosol

What type of process is glycolysis

catabolic

Explain oxidation of pyruvate to actyl Coa

each pyruvate molecule loses one carbon atom with the release of carbon dioxide

What must be present in order for the oxidation of pyruvate to occur

oxygen

Where does the Calvin cycle occur

the stroma of the chloroplast.

What is the citric acidcycle

he mitochondrial hub for the final steps in carbon skeleton oxidative catabolism for carbohydrates, amino acids, and fatty acids.

How does the citric acid cycle work

serves as the mitochondrial hub for the final steps in carbon skeleton oxidative catabolism for carbohydrates, amino acids, and fatty acids.

what molecules link glycolysis and citric acid cycle to oxidative phosphorylation

pyruvate

What is oxidative phosphorlation

a cellular process that harnesses the reduction of oxygen to generate high-energy phosphate bonds in the form of adenosine triphosphate (ATP).