A&P CH2 PG13

This is a continuation of PG12 and the importance of water in inorganic chemistry: 2 reactions involving water

Reactions involving water

• Hydrolysis

• Dehydration synthesis

Water plays a major role in maintaining ____ temperature.

Maintaining body temperature

What does the body do to maintain body temperature?

• Sweating

• Evaporation of perspiration for cooling

What is specific heat?

The amount of heat needed to raise the temperature of a substance by 1°C

Water has a relatively____ specific heat.

High

What does it mean for water to have a high specific heat?

• It takes a LOT of energy to heat water

• Body temperature changes slowly

What makes water have high specific heat?

It is due to hydrogen bonds;

energy is used to break hydrogen bonds before temperature rises.

How does water having high specific heat help the body?

1. it prevents sudden temperature changes

2. Absorbs heat produced by metabolism

3. Keeps enzymes working properly

What is Heat of Vaporization?

The amount of heat needed to turn liquid into gas

Water has a ____ heat of vaporization

High heat

What does it mean for water to have a high heat of vaporization?

1. A lot of heat is required for sweat to evaporate

2. When sweat evaporates, it removes heat from skin

How does specific heat and heat of vaporization work together to help regulate body temperature homeostasis? (Sweating)

1. Body temperature rises

2. Sweat glands release sweat

3. Sweat evaporates

4. Hear leaves the body

5. Body cools

High Specific Heat or High Heat of Vaporization?:

Prevents rapid heating

High Specific Heat

High Specific Heat or High Heat of Vaporization?:

Allows cooling by sweat

High Heat of Vaporization

What is Lubrication?

The natural, fluid-based systems that reduce friction between moving tissues, surfaces, and joints to prevent wear, damage, and pain

What is an example of a lubricant in the body?

1. Pleural fluid (lungs)

2. Joint fluid (synovial fluid)

3. Peritoneal fluid (abdomen)

4. Mucus membranes

5. Tears (eyes)

6. Saliva (mouth )

7. Sebum (skin)

Water acts as a _________ in the body

Lubricant

Why does lubrication matter ?

1. Reduces friction

2. Prevents tissue damage

3. Allows smooth movement

What happens if there is not enough fluid?

1. Pain

2. Inflammation

3. Injury

What is pH?

the measure of acidity or alkalinity

• Based on hydrogen ion (H+) concentrations

What is the pH formula (simplified)?

pH = –log[H+]

What does the pH formula mean?

1. More H+ = lower pH = more acidic

2. Less H+ = higher pH= more basic

A pH scale of 0 – 6.9 is ______?

Acidic

A pH scale of 7 is _______?

Neutral

A pH scale of 7.1 – 14 is _____ (Alkaline)

Basic

What is normal blood pH range?

7.35-7.45 (slightly basic)

What does Acidic indicate?

1. High H+ concentrations

2. Low pH

3. Releases hydrogen ions

What are some examples of Acids?

1. Stomach acid (HCl)

2. Carbonic acid

3. Lactic acid

4. Vinegar (acetic acid)

Which is more acidic?:

pH 2 or pH 3

pH 2

Why is pH 2 more acidic than pH 3?

1. Each number = 10x change

2. pH 2 has 10x more H+ than pH 3

What is the Hydrogen concentration at pH 8?

1. pH = 8

2. [H+] = 10^-8 M

3. .00000001

Acidic, Neutral, or Basic?:

Blood

SLIGHTLY BASIC (7.35-7.45)

Why is pH homeostasis critical?

pH affects:

1. Enzyme activity

2. Protein shape

3. Cell function

4. Oxygen delivery

What happens if the pH is abnormal?

1. Confusion

2. Coma

3. Cardiac arrest

4. Death

How does the body maintain homeostasis?

1. Buffer systems (immediate response)

2. Lungs (respiratory control)

3. Kidneys (Renal Control)

how do bicarbonate Buffer systems maintain pH homeostasis?

1. Uses HCO3 - and CO2

2. Neutralizes acids/bases

How do lungs maintain pH homeostasis?

1. Removes CO2

2. CO2 affects acid levels

How do kidneys maintain pH homeostasis

1. Removes or retain H+

2. Adjust bicarbonate

3. Slow but powerful