BIOL B11 Chapter 5 The Working Cell

The ATP cycle can run at an astonishing pace of about _____________ ATPs are consumed and recycled each second in a working muscle cell.

10 million

The label on a candy bar says that it contains 150 Calories. If you could convert all of that energy to heat, you could raise the temperature of how much water by lS°C?

10,000 g (or 10 kg); remember that 1 calorie on a food label equals 1,000 calories of heat energy.

chemical energy released by the breakdown of organic molecules during cellular respiration is used to generate molecules of:

ATP

made out of three phosphate molecules. Is called adenosine triphosphate

ATP

what molecule is the usual energy source for active transport?

ATP

Explain how ATP powers cellular work.

ATP transfers a phosphate group to another molecule, increasing that molecule's energy content.

the tripohsophate tail is the _____________ end of ATP, provides energy for cellular work.

business

units of energy, the amount of energy that can raise the temperature of 1 gram of water by 1 C.

calorie

exocytosis example:

cells in your tear glands use exocytosis to export the salty tears. In a grain the exocytosis of neurotransmitter chemicals such as dopamine helps neutrons communicate.

ATP powers:

celluar work

the molecules of food, gasoline, and other fuels have a form of energy called: which arises from the arrangement of atoms and can be released by a chemical reaction. Carbohydrates, fats, and gasoline have structures that make them especially rich in chemical energy.

chemical energy

this process breaks organic fuel into smaller waste molecules that have much less chemical energy than the fuel molecules did, thereby releasing energy that can be used to perform work.

chemical energy

What is the source o f energy for regenerating ATP from ADP?

chemical energy harvested from sugars and other organic fuels via cellular respiration

Cellular work spends ATP, which is recycled when ADP and phosphate are:

combined using energy released by cellular respiration

living organisms can transform kinetic energy to potential energy and vice versa

conservation of energy

physical principle that explains that it is not possible to destroy or create energy. Energy can only be converted from one form to another.

conservation of energy

In energy transformations, total energy is:

conserved

energy cannot be created or destoryed, where has the energy gone in an example when the diver hits the water?

converted to heat

Molecules are restless, they constantly vibrate and wander randomly. One result of the motion is _____________, the movement of molecules spreading out evenly into the available space.

diffusion

In what ways does directed evolution mimic natural selection? In what ways does it differ?

directed evolution, as with natural selection, involves reproduction and variation. It differs in that scientists perform tests to determine which variations are most fit.

What happens if an animal cell is in contact with a hypotonic solution which has a lower solute concentration than the cell?

due to osmosis the cell would gain water, swell, and possibly burst (lyse) like an overfilled water balloon

a cell takes in the material by vesicles that bud inward. can also be triggered by the binding of certain external molecules to specific receptor proteins built into the plasma membrane.

endocytosis

makes things happen psychologically and physically

energy

the capacity to cause change. So e forms are used to perform work, such as moving an object against an opposing force.

energy

In what sense is active transport "active"?

energy must be expended for the reaction to proceed

____________ is the capacity to perform work, while ___________ is a measure of randomness.

energy; entropy

The transformation of potential to kinetic create heat therefore increasing:

entropy

a measure of the amount of disorder, or randomness in a system.

entropy

everytime energy is converted from one form to another, _____________ increases.

entropy

the energy transformations during the climb up the ladder and the dive from the platform increased _________ as the diver emitted heat to the surroundings.

entropy

certain molecules can inhibit a metabolic reaction by binding to an enzyme and disrupting its function

enzyme inhibitors

almost all enzymes are ______________, but some RNA molecules also function as enzymes.

enzymes

almost no metabolic reactions occur without help. Most require the assistance of ____________, which are molecules that speed up chemical reactions without being consumed by those reactions

enzymes

During protein production by the cell, secretory proteins exit the cell from transport vesicles that fuse with the plasma membrane, spilling the contents outside the cell. this process is called:

exocytosis

substances that do not cross membranes spontaneously can be transported by proteins that act as corridors for specific molecules. This assisted transport is called:

facilitated diffusion

using calories to describe the fuel content of foods is not practical because they are tiny units of energy. Instead it's conventional to use _______________, units of 1,000 calories.

kilocalories

A diver to get to the top of the diving board must work to overcome the opposing force of gravity. In this specific case, chemical energy from food is converted to what kind of energy?

kinetic energy

the energy of motion

kinetic enrgy

energy from the sun that makes things grow

light energy

how does an enzyme recognized its substrate?

the substrate and the enzyme's active site are complementary in shape and chemistry.

Each kind of enzyme has a unique _____________________ ____________ that determines what specific chemical reaction the enzyme promotes.

three-dimensional shape

life depends on countless similar __________________ _____ _____________ from one form to another

transformations of energy

what would happen if you placed one of your cells in pure water?

water would rush in and would burst the cell

Describe the energy transformations that occur when you climb to the top of a stairway.

you transform the chemical energy from food to the kinetic energy of your upward climb. At the top of the stairs, some of the energy has been stored as potential energy because of your higher elevation. The rest has been transformed to heat.

What does it mean to say that molecules move "down the concentration gradient?"

the molecules move from where it is more concentrated to where it is less concentrated

What creates heat or thermal energy?

the movement of random motion of atoms and molecules that are always moving. The faster atoms and molecules move, the more heat produced.

about how long would you have to ride your bicycle to burn off the energy in one slice of pizza?

1 hour (riding a bicycle burns about 150 calories each half hour and a slice of pizza is about 300 calories

After the release of the phosphate at the tip of the triphosphate tail making energy available to working cells, what remains is called ______, adenosine diphosphate (two phosphate groups instead of three.)

ADP

Chemical energy released by the breakdown of organic molecules during cellular respiration is used to generate molecules of:

ATP

When a target molecule accepts the third phosphate group from the _________, it becomes energized and can then perform work in the cell.

ATP

acts like a battery, stores energy obtained from food, and releases it later as needed for cell work.

ATP

Explain how an inhibitor can disrupt an enzyme's action w ithout binding to the active site.

An inhibitor's binding to another site on the enzyme can cause the enzyme's active site to change shape.

What are enzymes? Using an example from the text explain how enzymes work.

Enzymes are proteins that speed up chemical reactions by reducing the amount of activation needed to break bonds of reactant molecules. Enzymes assist in the metabolic reactions of an organism. Each enzyme promotes a different chemical reaction depending on the organism or location in the body. Essentially the way enzymes work is through a sort of lock and key method. Enzyme proteins that are ready for substrates which could be lactose molecules for example, bind to them at a spot in the Enzyme called the active site. Once the substrate and enzyme are bound, water is added to the catalysis and the substrate (lactose) is broken down into glucose and galactose. Enzymes release the broken down substrate and are free to break down other substrates.

a type of kinetic energy contained in the random motion of atoms and molecules which are always moving about.

Heat energy

Your digestive system uses a variety of enzymes to break down large food molecules into smaller ones that your cells can assimilate. A generic name for a digestive enzyme is hydrolase. What is the chemical basis for that namel (Hint: Review Figure 3.4.)

Hydrolases are enzymes that participate in hydrolysis reactions, breaking down large molecules into the smaller molecules that make them up. Enzymes often have names that end in -ase, so a hydrolase is an enzyme that performs hydrolysis reactions.

Explain why it is not enough to say that a solution is "hypertonic.•

Hypertonic and hypotonic are relative terms. A solution that is hypertonic to tap water could be hypotonic to seawater. When using these terms, you must provide a comparison, as in "The solution is hypertonic to the cell's cytoplasm."

why is facilitated diffusion a form of passive transport?

It uses proteins to transport materials down a concentration gradient without expending energy

Identify the term called stored energy_______. Using an example show how it works.

Potential energy is stored energy. The way it works is when something or someone is in a position that could potentially generate kinetic energy, they are at a point with high potential for energy. For example, someone on top of a diving board has a greater potential energy than someone already in the lake as the person who jumps off the diving board is in the process of converting that potential energy into kinetic energy. It's a flow, or a transformation of energy that goes hand and hand hence why I speak of kinetic energy. The potential energy is stored because it has not been used yet. When the energy is being used by falling from the board, that is energy of motion, the kinetic energy.

Energy cannot be created or destroyed >>>>> Energy can be converted from one form to another. This is the principle of:

Principle of Conservation Energy

Diffusion of molecules across a membrane without the use of energy is called__________. How does this work?

The Diffusion of molecules across a membrane without the use of energy is called Passive Transport. In Passive Transport a substance diffuses down its concentration gradient from where the substance is more concentrated to where it is less concentrated. For example, there may be more sodium inside a cell than outside the cell, therefore the sodium will passively transport through the membrane til the amount of sodium outside and inside the cell is the same.

Enzymes unravel and stop functioning if the environment gets too hot.

The relationship of structure to function: What an enzyme does (its function) depends upon it having a particular shape (its structure)

Identify the primary source of energy for the cell. Explain, what makes this source of energy better than other sources of energy.

The primary source of energy for the cell is adenosine triphosphate or ATP. ATP acts like a battery, stores energy obtained from food, and releases it later as needed for cell work. ATP has three phosphate molecules. During the transference of energy, ATP loses a phosphate molecule becoming ADP. Energy often produces a certain degree of heat, and ATP has a mechanism to maintain the level of energy to where heat does not build up, thereby not destroying the cell by overheating from energy.

Why does removing a phosphate group from the triphosphate tail in a molecule of ATP release energy?

The three phosphate groups store chemical energy, a form of potential energy. The release of a phosphate group makes some of this potential energy available to cells to perform work.

The control of water balance is called Osmoregulation. Identify three types of Osmotic Environments and their characteristic effect on cells

The three types of osmotic environments are isotonic solution, hypotonic solution, and hypertonic solution. Isotonic solutions are solutions of equal solute concentration. If a plant cell is immersed in an isotonic solution it becomes flaccid and the plant cell wilts. An animal cell thrives in an isotonic environment and looks very normal here. hypotonic solutions are solutions with lower solute concentration and higher water concentration. A plant cell immersed in a hypotonic solution is turgid and healthiest with a net inflow of water. An animal cell on the other hand becomes lysed in a hypotonic environment. hypertonic solution is a solution that has a higher concentration of solute. Both plant and animal cells fair the same in a hypertonic solution, as they both become very shriveled from loss of water and the plasma membrane pulls away from the cell wall killing the cell.

Can an object at rest have energy?

Yes, it can have potential energy because of its location or structure

Enzymes enable metabolism to occur by reducing the amount of _______________ _____________ required to break the bonds of reactant molecules.

activation energy

The energy that must be invested to start a reaction is called ______________ __________ because it activates the reactants and triggers the chemical reaciton.

activation energy

requires a cell expend energy to move molecules across a membrane. Cellular energy is used to drive a transport protein that pumps a solute against the concentration gradient.

active transport

How does an enzyme affect the activation energy of a chemical reaction?

an enzyme lowers the activation energy

Which of these types of cellular transport require(s) energy? a. facilitated diffusion b. active transport c. osmosis d. a and b

b. active transport

If someone at the other end of a room smokes a cigarette, you may breathe in some smoke. The movement of smoke is similar to what type of transport? a. osmosis b. diffusion c. facilitated diffusion d. active transport

b. diffusion

stored energy. It is energy that an object has because of its location

potiential energy

energy that enables us to move and to stay warm in the cold

food energy

supplies power to automobile engines

fuel energy

Getting into the texbook questions now

getting into the textbook questions now

The friction between the body and its surroundings generated _________ in the air and then in the water.

heat

Which form of energy is most randomized and difficult to put to work?

heat

a type of kinetic enregy contained in the random motion of atoms and molecules

heat

Imagine a membrane separating two solutions with different concentrations of a solute. The solution with a higher concentration of solute is said to be _______________ to the other solution.

hypertonic

An animal cell shrivels when it is ____________ compared with its environment.

hypotonic

The soltuion with the lower solute concentration is said to be __________ to the other.

hypotonic

the interaction between the active site and the substrate where the enzyme works to catalyze the reaction by changing its shape at the active site slightly to embrace the substrate. the entry of the substrate induces the enzyme to change shape slightly, making the fit between the two snugger.

induced fit

Your ability to walk depends upon the coordination of many different enzymes and other cellular structures.

interactions within biological systems: Many differnt parts of the human body must interact in order to produce an overall outcome (such as muscle movement).

Solutions of equal solute concentration are said to be:

isotonic

how can enzyme inhibitors cause damage?

many toxins and poisons also work as inhibitors. Nerve gases irreversibly bind to the active site of an enzyme vital to transmitting nerve impulses leading to rapid paralysis and death. Many pesticides are toxic to insects because they inhibit this same enzyme.

The total of all the chemical reactions in an organism is called:

metabolism

Dehydration can cause fatigue and even death. Drinking too much water (called hyponatremia) called water intoxication, can also cause death by overdiluting necessary ions. These are the failure of what in the human body?

osmoregulation

the control of water balance; for example a freshwater fish has kidneys and gills that work constantly to prevent an excessive buildup of water in the body.

osmoregulation

diffusion of water across a selectively permeable membrane is called:

osmosis

_____________ ______________ is passive because no energy is needed for the diffusion to happen. a substance diffuses down its concentration gradient from where the substance is more concentrated to where it is less concentrated.

passive transport

diffusion of dye across a membrane is an example of:

passive transport

What is the primary difference between passive and active transport in terms of concentration gradients?

passive transport moves atoms or molecules along their concentration gradient (from higher to lower concentration), and active transport moves them against their concentration gradient.

You turn the crank of a well, raising a bucket of water from below ground to the surface.

pathways that transform energy and matter: You are burning food energy to change the position of the water, which is gaining potential energy

how can enzyme inhibitors in medicine be beneficial?

penicillin blocks the active site of an enzyme that bacteria use in making cell walls. Ibuprofen inhibits an enzyme involved in sending pain signals. Many cancer drugs inhibit enzymes that promote cell division.

a cell engulfs a particle and packages it within a food vacuole. other times a cell gulps droplets of fluid into vesicle.

phagocytosis

For ATP power, it is release of the ______________ at the tip of the triphosphate tail that makes energy available to working cells.

phosphate

ATP is renewable, can be stored by adding a ______________ __________ back to ADP that takes energy, like recompressing a spring.

phosphate group

The kinetic energy of muscle movement is storedas this type of energy; the energy that an object has because of its location or structure.

potential energy

the energy behind a dam and energy stored by a compressed spring are examples of

potential energy

a substance that is dissolved in a liquid solvent, and the resulting mixture is called a solution.

solute

An enzyme is very selective in the reaction it catalyzes. The specific molecule that an enzyme acts on is called the enzyme's:

substrate

The chemical energy that cellular respiration harvests from from sugars and other organic fuels is put to work regenerating a cell's:

supply of ATP