1.As much as you can, compare and contrast the animal and plant cell.

2.Compare mitosis and meiosis.3.Translate to other DNA strand:

GAC CTA GGT ACT4.Translate to RNA strand (see #3)

WARM-UP

Section 17.1THE FLOW OF ENERGY

7.a. Students know how to describe temperature and heat flow in terms of the motion of molecules (or atoms)

7.b. Students know chemical processes can either release (exothermic) or absorb (endothermic) thermal energy

STANDARDS

Thermochemistry: the study of energy changes that occur during chemical reactions and changes in state.

Chemical Potential Energy: the energy stored in chemical bonds of a substance

ENERGY TRANSFORMATIONS

During a chemical reaction, a substance is transformed into another substance, with a different amount of chemical potential energy.

Heat, represented by “q”: energy that transfers from one object to another because of a temperature difference between them

ENERGY TRANSFORMATIONS

Heat always flows from warmer object to a cooler object.

ENERGY TRANSFORMATIONS

System: the part of the universe on which you focus your attention

Surroundings: everything else in the universe

EXOTHERMIC AND ENDOTHERMIC

Law of conservation of energy: states that in any chemical or physical process energy is neither created nor destroyed

Endothermic process: once that absorbs heat from its surroundingsIn an endothermic process: the system gains heat as the surroundings cool down

EXOTHERMIC AND ENDOTHERMIC PROCESSES

Exothermic process: one that releases heat to its surroundingsIn an exothermic process, the system loses heat as the surroundings heat up

EXOTHERMIC AND ENDOTHERMIC PROCESSES

Endothermic = “q” is positiveExothermic = “q” is negative

FIGURE 17.1

PRACTICE PROBLEM 1 & 2

Heat flow is measure in two common units:The calorieThe Joule

One dietary calorie = 1 kilocalorie (1000 calories)

The Joule is the SI unit of energy1 J = 0.2390 cal4.184 J = 1 cal

UNITS FOR MEASURING HEAT FLOW

Heat capacity: amount of heat needed to increase the temperature of an object exactly 1o CThe heat capacity of an object depends on both its mass and chemical composition

Specific heat: amount of heat it takes to raise the temperature of 1 g of the substance 1oC

HEAT CAPACITY AND SPECIFIC HEAT

FIGURE 17.4

Water releases a lot of heat as it cools. During freezing weather, farmers protect citrus crops by spraying them with water. The ice that forms has a protective effect as long as the temp does not go below 0.

Because it it mostly water, the filling of a hot apple pie is much more likely to burn your tongue than the crust.

Q = mCΔTHeat = mass x specific heat x change in temperature

HEAT CAPACITY AND SPECIFIC HEAT

SAMPLE PROBLEM #3

SAMPLE PROBLEMS 4, 5 & 6

Pg 24 17.1 Assessment, #5-11, PG 27 #38-47

IN CLASS