Chapter 2 Flashcards
1
Q
Matter
A
Anything that has mass and occupies space
2
Q
Weight
A
The pull of gravity on mass
3
Q
States of Matter
A
Solid
Liquid
Gas
4
Q
Energy
A
The capacity to do work or put matter into motion
5
Q
Types of Energy
A
Kinetic
Potential
6
Q
Forms of Energy
A
Chemical- stored in bonds of chemical substances
Electrical- Results from movement of charged particles
Mechanical- Directly involved in moving matter
Radiant- Travels in waves (ultraviolet light)
7
Q
Energy form Conversion
A
- May be converted from one form to another
- Conversion is inefficient (some energy is lost as heat)
8
Q
Elements
A
Matter is elements
Cannot be broken into simpler substances by ordinary chemical methods
9
Q
Human Body Elements (4)
A
Oxygen Carbon Hydrogen Nitrogen 96% of the human body
10
Q
Atoms (overall)
A
Building blocks for each element
Gives each element its physical and chemical properties
Smallest particles of an element with properties of that element
11
Q
Atoms (make-up)
A
composed of subatomic particles- protons, neutrons, and electrons
Protons and Neutrons found in nucleus
Electrons orbit nucleus in an electron cloud
12
Q
Atom (nucleus)
A
Almost entire mass of the atom
Neutrons- Carry no charge
Protons- Carry positive charge
13
Q
Atom (electrons)
A
Electrons orbit within electron cloud
- carry a negative charge
- 1/2000 the mass of a proton
- number of protons and electrons always equal
14
Q
Atom (models)
A
Planetary model-2D simplified; outdated
Orbital model-3D current model, used by chemists
15
Q
Isotyopes
A
Structural variations of atoms
Differ in the number of neutrons they contain
Atomic numbers same; mass numbers different
16
Q
Atomic Weight
A
Average of mass numbers (relative weights) of all isotopes of an atom
17
Q
Molecule vs. Compound
A
Molecule- 1 type
Compound- multiple types (at least 1)
18
Q
Mixtures
A
Two or more components physically intermixed
-most matter exists as mixture
19
Q
3 Types of Mixtures
A
Solutions
Colloids
Suspensions
20
Q
Solutions
A
Homogeneous mixtures
Solvent- greatest substance, if a liquid; usually water
Solute- present in smaller amounts
21
Q
Colloids
A
Heterogeneous mixtures
Larger solute particles do not settle out
22
Q
Suspensions
A
Heterogeneous mixtures (blood) Large, visible solutes settle out
23
Q
Mixtures Vs. Compounds
A
Mixture: -No chemical bonding between components -Can be separated -Heterogeneous or Homogeneous Compound: -Chemical bonding between components -Can be separated -All are homogeneous
24
Q
Chemical Bonds
A
Energy relationships
Electrons can occupy up to 7 electron shells
Electrons in Valence Shell (outermost electron shell)
-have most potential energy
-are chemically reactive electrons
25
Chemically Inert Elements
Stable and unreactive
Valence shell fully occupied or contains eight electrons
Noble Gases
26
Chemically Reactive Elements
Valence shell not full
| Tend to gain, lose, or share electrons (form bonds) with other atoms achieve stability
27
Types of Chemical Bonds (3)
Ionic
Covalent
Hydrogen
28
Ionic Bonds
Ions
-atoms gain or lose electrons and becomes charged
Transfer of electrons from one atom to another forms ions
-Anion (negative charge)
-- atoms gains at least one electron
-Cation (positive charge)
-- atoms loses at least one electron
29
Ionic Compounds
Most ionic compounds are salts
-when dry salts form crystals instead of individual molecules
Ex. NaCl (sodium chloride)
30
Covalent Bonds
Formed by sharing of two or more electrons
| Allows each atom to fill its valence shell at least part of the time
31
Ionic Vs. Covalent
Ionic- giving
| Covalent- sharing
32
Hydrogen Bonds
Attractive force between electropositive hydrogen of one molecule and an electronegative atom of another molecule
- not true bond
- common in water
- also acts as intramolecular bonds, holding a large molecule in a 3D shape
33
Chemical Reactions
Occur when chemical bonds are formed, rearranged, or broken
| -Reaction is the combination of formed, rearranged, or broken
34
Patterns of Chemical Reactions
Synthesis (combination) reaction
Decomposition reactions
Exchange reactions
35
Synthesis Reactions
A + B = AB
- Atoms or molecules combine to form larger, more complex molecule
- Always involve bond formation
- Anabolic
36
Decomposition Reactions
AB = A + B
- Molecule is broken down into smaller molecules or its constituent atoms
- -Reverse of synthesis reactions
- Involving breaking of bonds
- Catabolic
37
Exchange Reactions
AB + C = AC + B
- Also called displacement reactions
- Involve both synthesis and decomposition
- Bonds are both made and broken
38
Energy Flow in Chemical Reactions
| Two Types
All chemical reactions are either exergonic or endergonic
- Exergonic Reactions- Exer- Exit leaving
- -net release of energy
- -products have less potential energy than reactants
- -catabolic and oxidative reactions
- Endergonic Reactions- Ender- Enter gaining/absorbing
- -net absorption or energy
- -products have more potential energy than reactants
- -Anabolic reactions
39
Reversibility of Chemical Reactions
```
Chemical equilibrium
AB = A + B
A + B = AB
Many biological reactions are essentially irreversible
-due to energy requirements
-due to removal of products
```
40
Rate of Chemical Reactions
Affected by
- Rising Temperature = Rising Rate
- Rising Concentration of Reactant = Rising Rate
- Lowering Particle Size= Rising Rate
- Catalysts: Rising Rate without being chemically changed or part of product
- -enzymes are biological catalysts
41
Biochemistry
Study of chemical composition and reactions of living matter
| All chemicals either organic or inorganic
42
Classes of Compounds
Inorganic- water, salts,and many acids and bases; does not contain carbon
Organic- carbohydrates, fats, proteins, and nucleic acids; contains carbon
Both equally essential for life
43
Water in Living Organisms
Most abundant inorganic compound
Most important inorganic compound
-due to water's properties
44
Properties of Water
High heat capacity
-absorbs and release heat with little temperature change
-prevents sudden changes in temperature
High heat evaporation
-evaporation requires large amounts of heat
-useful cooling mechanism
Polar solvent properties
-universal solvent
-dissolves and dissociates ionic substances
-body's major transport medium
Cushioning
-protects certain organs from physical trauma (cerebrospinal fluid)
45
Salts
Ionic compounds that dissociate into ions in water
- ions (electrolytes) conduct electrical currents in solution
- ions plat specialized roles in body functions
- ionic balance vital for homeostasis
46
Acids and Bases
```
Both are electrolytes
Acids- proton donors
- release in H+ solution
Bases- proton acceptors
-Take up H+ from solution
```
47
pH: Acid base Concentration
-Free H+ of a solution measured on pH scale
-As free H+ increases, acidity increases
-As free H+ decreases alkalinity increases
pH= negative logarithm of H+ in mole per liter
pH scare ranges from 0-14
48
pH: Levels
```
Acidic Solutions
-rising H+, lower pH
-acidic pH = 0- 6.99
Neutral Solutions
- equal number of H+ and OH-
- All neutral solutions are pH 7
-pure water is pH neutral
Alkaline (basic) Solutions
-lowering H+, higher pH
-Alkaline pH = 7.01-14
```
49
Neutralization
Mixing acids and bases
- forming water and a salt
- neutralization reaction
50
Acid-Base Homeostasis
- pH change interferes with cell function and may damage living tissue
- Even slight change in pH can be fatal
- pH is regulated by kidneys, lungs, and chemical buffers
51
Organic Compounds
Molecules that contain carbon
-except CO2 and Co, which are considered inorganic
-Carbon is electroneutral
Unique to living systems
Carbohydrates, lipids, proteins, and nucleic acids
52
Carbohydrates
```
Sugars and starches
Polymers
Three classes:
-Monosaccharides
-Disaccharides
-Polysaccharides
Function- cellular fuel
-Ex. glucose
```
53
Disaccharides
```
Double sugars
Too large to pass through cell membranes
Important disaccharides
-sucrose
-maltose
-lactose
```
54
Polysaccharides
Polymers of monosaccharides
Important polysaccharides
-starch and glycogen
Not very soluble
55
Lipids
```
Insoluble in water
Main Types:
-Triglycerides or neutral fats
-Phospholipids
-Steroids
-Eicosanoids
```
56
Triglycerides
Energy storage
Insulation
Protection
57
Phospholipids
Important in cell membrane structure
58
Steroids
Interlocking 4-ring structure
Cholesterol, vitamin D, steroid hormones, and bile salts
Most important steroid is Cholesterol
59
Eicosanoids
Prostaglandin (most important eicosanoid
| -Role in blood clotting, control of blood pressure, inflammation, and labor contractions
60
Other Lipids in the Body
Other fat-soluble vitamins (A, D, E, K)
| Lipoproteins- transport fats in the blood
61
Proteins
```
Proteins are polymers
Amino acids (20 types) are the monomers in proteins
```
62
Fibrous Proteins
- Structural
- Strandlike, water-insoluble, and stable
- Provide mechanical support and tensile strength
- Ex. keratin, elastin, collagen
63
Globular Proteins
- Functional
- 3D structure
- Specific functional regions (active sites)
- Ex. antibodies, hormones, molecular chaperons, and enzymes
64
Protein Denaturation
Proteins unfold and lose function-active sites destroyed
Can be caused by decreased pH or increased temperature
Usually reversible if normal conditions restore
Irreversible if changes extreme
-Ex. Cooking an egg
65
Enzymes
Proteins that act as biological catalysts
-regulate and increase speed of chemical reactions
Lower the activation energy, increase the speed of a reaction
66
Characteristics of Enzymes
Usually end in -ase
Often named for the reaction they catalyze
-Ex. hydrolases, oxidases
67
Nucleic Acids
```
Deoxyribonucleic Acid (DNA)
Ribonucleic Acid (RNA)
largest molecules in the body
```
68
Deoxyribonucleic Acid (DNA)
Located within the nucleus
Utilizes 4 nitrogen bases
-Adenine (A), Guanine (G)
-Cytosine (C), Thymine (T)
--base pair rule- each base pair with its complementary base (A and T); (G and C)
Double-stranded helical molecule (double helix) in the cell nucleus
Provides instructions for all protein synthesis
Replicates before cell division ensuring genetic continuity
69
Ribonucleic RNA
```
Located outside the nucleus
Utilizes 4 nitrogen bases
-Cytosine (C), Guanine (G)
-Adenine (A), Uracil (U)
Single-stranded molecule
Three varieties of RNA carry out the DNA orders for protein synthesis
```
70
Adenosine Triphosphate (ATP)
Chemical energy in glucose captured in this important molecule
Directly powers chemical reactions in cells
Energy form immediately usable by all body cells
Structure of ATP
-Adenine-containing RNA nucleotide with two additional phosphate groups
71
Function of ATP
Phosphorylation:
- Terminal phosphates are enzymatically transferred to and energize other molecules
- Such "primed" molecules perform cellular work (life processes) using the phosphate bond energy
