Biophysics 6

Front 1

What is energy?

Back 1

The ability to do work, produce movement or activity.

Front 2

6 types of energy

Back 2

mechanical

chemical

heat

electrical

electromagnetic

nuclear

Front 3

What is a device that converts energy from one form to another in a predictable way called?

Back 3

Transducer

Front 4

Give an example of a transducer and explain how it works.

Back 4

Receptors

Specialised cell that responds to a variable feature of an animals internal or external environment (stimulus) by a shift in membrane potential.

Front 5

What do receptors do?

Back 5

convert physical energy into an electrical current and encode it from analogue to digital signal

Front 6

What is the study of the behaviour of heat and energy and the ways that different forms of energy turn into heat called?

Back 6

Thermodynamics

Front 7

How many laws of thermodynamics are there?

Back 7

4

Front 8

Define the first law of thermodynamics.

Back 8

energy can neither be created nor destroyed but can be converted from one form to another or transferred from one system to another.

Front 9

Second Law of thermodynamics

Back 9

Difference in temperature, pressure and chemical potential tend to equilibrate in an isolated physical system.

Front 10

Third Law of thermodynamics

Back 10

Entropy of a system approaches zero as its temperature approaches absolute zero.

Front 11

Zeroth Law of Thermodynamics

Back 11

If two bodies are in thermal equilibrium with a third body then they are also in thermal equilibrium with one and other.

Front 12

Enthalpy

Back 12

Measure of energy content of a system.

Front 13

Internal energy depends on which three variables?

Back 13

Volume

Temp

Pressure

Front 14

Compare Isobaric and Isochodric

Back 14

Isobaric

Constant pressure. Change in enthalpy equals change in internal energy and work done on surroundings.

Isochoric

Constant volume. Change in enthalpy equals change in internal energy.

Front 15

What concept does the Carnot engine apply?

Back 15

Ideal heat concept.

Front 16

Ideal heat concept

Back 16

determines how much heat can be produced in the steam engine. Sets an upper limit to the efficiency of any real engine.

Front 17

Name the four stages of the Carnot cycle

Back 17

AB- isothermal expansion

BC- adibatic expansion

CD- Isothermal compression

DA- Adibatic compression

Front 18

What is Adibatics?

Back 18

Process that takes place without the loss or gain of heat.

Front 19

What must a change in pressure or volume be accompanied by?

Back 19

Temperature

Front 20

Why must a change in volume or pressure be accompanied by a change in temp in an adibatic system?

Back 20

Because adibatics occur without the transfer of heat.

Front 21

Is adibatics a rapid or slow process?

Back 21

Rapid

Front 22

How does a heat engine work?

Back 22

By drawing heat from a hot body and rejecting it into a cooler body.

Furnace -> condensor

Front 23

What is the difference between a heat and reversible engine?

Back 23

In a heat engine the process only works one way. In a reversible engine the same amount or work is performed whether the cycle goes forwards or backwards.

Front 24

Are natural processes reversible?

Back 24

No

Front 25

What do natural systems tend towards?

Back 25

Towards ever increasing disorder.

Front 26

What happens when entropy increases?

Back 26

There is a simultaneous loss in available energy.

Front 27

Name three processes involved in an increase in entropy.

Back 27

Radiation

Convection

Conduction

Front 28

What is a heat pump?

Back 28

An engine that transfers heat from a hot object to a heat sink.

Front 29

Define temperature.

Back 29

A physical property that quantitatively expresses the statistical distribution and the mean value of kinetic energy or particles of matter.

Front 30

What happens to particles at absolute zero?

Back 30

particles have no kinetic energy

Front 31

What is the name of the study of material at very low temperatures?

Back 31

Cryogenics

Front 32

What happens to superconductors at very low temperatures?

Back 32

They lose their electrical resistance almost completely.

Front 33

What is the Meissner effect?

Back 33

A superconductor will not allow a small magnetic field to penetrate inside it, instead as currents begin to circulate in a thin layer on it's surface, creating a magnetic field that exactly cancels out the applied field inside the conductor.

Front 34

What substance is a superfluid?

Back 34

Liquid helium at temperatures near absolute zero.

Front 35

What are the properties of a superfluid?

Back 35

Almost no viscosity. Elephantine thermal conductivity. No friction in small capillaries.

Front 36

What creates pressure in a gas?

Back 36

Particles colliding with each other and the walls of their container.

Front 37

What effect does heat have on the pressure of a gas?

Back 37

increases pressure

Front 38

What is Boyle's law?

Back 38

For a fixed amount of an ideal gas kept at a fixed temperature. Pressure and volume are inversely proportional.

Front 39

What is Charles's law?

Back 39

At constant pressure the volume of a given mass of an ideal gas increases and decreases by the same factor as its temperature on the absolute temperature scale.

Front 40

What is the pressure law?

Back 40

In a mixture of ideal gasses. Each gas has a partial pressure which is the pressure that the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the individual partial pressures.

Front 41

Radiation

Back 41

Electromagnetic waves transferred through a transparent media.

The only type of heat that can travel through a vacuum.

Front 42

Convection

Back 42

Bulk movement of atoms/molecules. Occurs in fluids.

Front 43

Conduction

Back 43

Transfer of heat through increasing kinetic energy without bulk movement of atoms or molecules. Solids.

Front 44

What form of energy is chemical energy?

Back 44

Potential

Front 45

What is it called when heat is released during a chemical reaction?

Back 45

Exothermic

Front 46

What is the opposite of an exothermic reaction?

Back 46

Endothermic reaction

Front 47

What is free energy?

Back 47

Amount of work that can be extracted from a system.

Front 48

Define calorific value

Back 48

The amount of heat given off when a unit amount of substance is completely burned.

Front 49

Direct Calorimetry

Back 49

Measure the heat change in a system. Thermally isolate the system to measure the temperature change.

Front 50

Indirect calorimetry

Back 50

calculated by the amount of CO2 produced by an organism.

Front 51

Give another name for the law of constant heat summation.

Back 51

Hess's law

Front 52

Hess's law

Back 52

the total amount of heat lost or gained by a system in any chemical reaction does not depend on the reaction mechanism, but only on the initial reactants and the final products.

Front 53

Name the three conservation laws.

Back 53

Conservation of mass

Conservation of linear momentum

Conservation of energy

Front 54

Is mass a form of energy?

Back 54

yes

Front 55

Name two things involved with nuclear physics.

Back 55

fission

nuclear physics