Harvill Bio 1305: Exam 2

Mitochondria

Site of ATP synthesis in animal cells. And contain the enzymes for cellular respiration

Nucleolus

Where rRNA synthesis happens

Glycoproteins

Molecules important to cell recognition/ identity its a protein with a carbohydrate attached usually found in the cell membrane

Desmosome

Anchoring junctions that prevent cells subjected to mechanical stress from being pulled apart; button like thickenings of adjacent plasma membranes connected by fine protein filaments

Golgi apparatus

Produces vesicles that replenish cell membranes. Think UPS they receive packages modify them a bit then ship them out.

Lipid A

Endotoxin component of gram negative cell walls

Cholesterol

Stabilizes cell membranes in mammals. Its a lipid and is hydrophobic and considered the precursor to steroids; estrogen and testosterone.

Cellulose

Component of plant cell walls made up of carbohydrates we can't digest it so its fiber

actin microfilaments

Forms the constriction between 2 new cells following mitosis. The diameter is 7nm Main function is cell motility. Think muscles.

Microtubules

A hollow rods composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella. Diameter is 25mn with 15 nm lumen. Think of spindle fibers during Mitosis.

intermediate filaments

fibrous proteins supercoiled into thicker cables. Diameter is 8-12 nm. Purpose is anchorage. Think about holding nucleus in place

Nucleus

Contains chromosomes (DNA + histones) Site of DNA synthesis

Plant AKA central vacuole

Starch storage site and holds water, ideally its turgid. to keep plant from wilting

Cell membrane

Composed of phospholipids and protein its semipermeable and allows most nonpolar molecules and very few small polar molecules like H2O. Site where aquaporins are found

Lysosomes

Contain digestive enzymes. They go to vesicles produces from phago and Pinocytosis and digest whatever is in there. They also eat bacteria found abundantly in saliva and immune cells.

Nucleoid

Site where bacterial DNA clumps

Smooth ER

Synthesis of fats and phospholipids, storage of calcium ions. Site where fats, steroids and phospholipids are made connected to rough but doesn't have any ribosomes.

Rough ER

Synthesis of proteins to be excreted by the cell. Covered in ribosomes (proteins factories)

Lipotechoic acids

Anchor peptidoglycan to the cell membrane

Integrins

Proteins that are Binding sites for fibronectin

Chloroplast

Site of photosynthesis; contains chlorophyll and accessory pigments. Inside they have little Pancake shaped things called thykoloids. It has stroma inside thats like its version of cytosol and it has its own DNA. Transform light E into the chemical energy of ATP

Capsule

Exterior carbohydrate composite that protects bacteria from the human immune system

Aquaporin

Integral protein important to osmosis. Its still passive transport just has a special name cos its water

Metabolism

The totality of an organism's chemical reactions

Metabolic Pathway

Begins with a specific molecule and ends with a product

Catabolic Pathway

Release energy by breaking down complex molecules into simpler compounds; creation of ATP (energy) (exergonic)

Cellular Respiration

The breakdown of glucose in the presence of oxygen (example of catabolic pathway) 3 not so easy steps; Glycolysis, Citric Acid Cycle, and the ETC (Oxidative phosphorlyzation).

Anabolic Pathway

Consume energy to build complex molecules from simpler ones; costs ATP (energy) (endergonic)

Energy

The capacity to cause change (work)

Kinetic energy

Energy about the movement of something (Heat, how fast particles are moving)

Potential energy

Energy about the location of something (bowling ball at top of stairs)

Kinetic energy produces ___________ energy.

Heat

Potential energy produces ____________ energy.

Chemical

First Law of Thermodynamics

States that the energy of the universe is constant

Second Law of Thermodynamics

Every energy transfer/transformation, some energy is unusable and lost as heat

Entropy

"disorder"

Heat

Causes molecules to move faster

Free energy

a measure of a system's instability, its tendency to change to a more stable state. Delta G is the change in free energy

Equilibrium

A state of maximum stability, if a cell is in it its dead.

negative; spontaneous

Only processes with a __________ delta G are ______________.

Work

Spontaneous processes can be used to perform ____________.

Exergonic

Reaction that proceeds with a net release of free energy and is spontaneous, the electron transport chain is this.

Endergonic

Reaction that absorbs free energy from its surroundings and is non spontaneous

Reactions in a closed system eventually reach ___________________ and then do no work

equilibrium

Open systems

Cells are not in equilibrium; they are ________ ____________ experiencing a constant flow of materials

Metabolism

__________________ is never at equilibrium.

Mechanical, Transport, and Chemical

The three main types of work

Energy Coupling

To do work, cells manage energy resources by ___________ ______________, the use of an exergonic process to drive an endergonic one

ATP

Most energy coupling in cells is mediated by _______.

ATP

The cell's energy shuttle

ATP

A nucleotide composed of ribose, adenine, and three phospholipids

Hydrolysis

When the bonds between the phosphate groups of ATP's tail are broken

Energy

Released from ATP when the terminal phosphate bond is broken

Chemical potential energy

The _____________ ______________ ___________ stored in ATP drives most cellular work

Catalyst

A chemical agent that speeds up a reaction without being consumed by the reaction

Protein

An enzyme is a catalytic ____________.

Activation energy (EA)

The initial energy needed to start a chemical reaction

lower

Enzymes _________ the EA barrier.

don't

Enzymes ________ affect the change in free energy

temperature, pH, and chemicals

What affects an enzyme's activity?

optimal temperature and pH

What does each enzyme have?

Coenzyme

organic cofactor (ex: vitamins) Helps the substrate fit

Cofactors

Any nonprotein molecule or ion that is required for the proper functioning of an enzyme. Cofactors can be permanently bound to the active site or may bind loosely with the substrate during catalysis

Competitive inhibitors

Bind to the active site of an enzyme, competing with the substrate; not permanent can be used for negative feedback

Noncompetitive inhibitors

Bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective; many are permanent can be used for negative feedback

Toxins, poisons, pesticides, and antibiotics are examples of?

Inhibitors

Metabolism within a cell is controlled by.....

switching on and off the genes

Allosteric Regulation

Occurs when a regulatory molecule binds to a protein at one site and affects the protein's function at another site

Polypeptide subunits

allosterically regulated enzymes are Mostly made from

Each enzyme has ___________ and _____________ forms.

active; inactive

Binding of an ___________ stabilizes the active form of the enzyme.

activator

Cooperativity

A form of allosteric regulation that can amplify enzyme activity

Feedback Inhibition

The end product of a metabolic pathway shuts down the pathway; prevents cells from wasting chemical resources by synthesizing more product than is needed

In cooperativity, binding by a ____________ to one active site stabilizes favorable conformational changes at all other subunits.

substrate

Enzymes

They are catalysts that lower the activation energy required for a reaction to occur and speed up the rate of the reaction. And can act as structural components of membrane.

Fermentation

Partial degradation of sugars; O2 not required

Aerobic respiration

Consumes organic molecules; requires O2 as the final electron acceptor; produces ATP

Anaerobic respiration

Uses a molecule other than oxygen as the final electron acceptor (bacteria)

transfer of electrons

The _________ ____ __________ during chemical reactions releases energy stored in organic molecules.

redox reactions

Chemical reaction that transfer electrons between reactants are called oxidation- reduction reactions

Oxidation

A substance that looses electrons

Reduction

A substance that gains electrons

Electron donor

The reducing agent

Electron acceptor

The oxidizing agent

NAD+

Electrons from organic compounds are usually first transferred to ______.

oxidizing

NAD+ functions as an _____________ agent during cellular respiration.

NADH

Each _________ (the reduced form of NAD+) represents stored energy that is tapped to synthesize ATP.

Glycolysis, citric acid cycle, and oxidative phosphorylation

The three stages of cellular respiration:

Glycolysis

Breaks down glucose into two molecules of pyruvate (every cell)

Citric acid cycle

Completes the breakdown of glucose

Oxidative phosphorylation

(accounts for most of the ATP synthesis) through the electron transport chain and chemiosmosis

Cellular respiration

90% of the ATP generated by....

redox

Powered by __________ reactions

electron transport chain

Occurs in the ____________ ___________ _______ in the inner membrane of the mitochondrion.

Cytoplasm

where glycolysis is located

energy investment phase; energy payoff phase

The two major phases of glycolysis:

Kinase

Enzymes transfer phosphate groups

Mitochondrion

In the presence of O2, pyruvate enters the ________________.

Mitochondrial matrix

Location of citric acid cycle

Pyruvate

The cycle oxidizes organic fuel derived from _________.