1 Introduction to Biology

2 Complexity of Life Biology is the study of life (bacteria, protists, fungi, plants, animals) Biology is the study of life (bacteria, protists, fungi, plants, animals) Subject is very complex Subject is very complex Scientists strive to understand living processes in order to improve and prolong life. Scientists strive to understand living processes in order to improve and prolong life. The more we learn about life, the more we appreciate its wonder! The more we learn about life, the more we appreciate its wonder!

3 All Living Things Share Common Characteristics 1. All organisms are made of cells - A cell is the smallest working unit - A cell is the smallest working unit of life. of life. Unicellular Unicellular Organisms Multicellula Multicellular Organisms

4 2. Reproduction Living things reproduce. If this did not occur, species wouldLiving things reproduce. If this did not occur, species would die out. Two types: sexual- two cells from different parents unite to produce the first cell of the new organism asexual – in which the new organism has a single parent.

5 3. Growth & Development All living things grow during at least part of their livesAll living things grow during at least part of their lives Growth - cell division and cell enlargement.Growth - occurs as the result of cell division and cell enlargement. Development – process through which an adult organism arises through repeated cell divisions and differentiation of those cells to form the various types of body cells.Development – process through which an adult organism arises through repeated cell divisions and differentiation of those cells to form the various types of body cells.

6 Growth & Development – What’s the Difference? Organisms grow by producing MORE CELLS & by cell ENLARGEMENT Organisms grow by producing MORE CELLS & by cell ENLARGEMENT Organisms develop as they mature into an adult organism Organisms develop as they mature into an adult organism

7 4. Energy Utilization organisms take in energy and transform it to do many kinds of work. Ultimate source is the sun. photosynthesis. Producers/Autotrophs convert sun’s energy into useable energy by a process called photosynthesis.

Most other organisms rely on the energy stored during photosynthesis – these organisms are known as heterotrophs. herbivores, carnivores, omnivores, and decomposers Examples - herbivores, carnivores, omnivores, and decomposers Energy Utilization – cont.

Metabolism - the combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes. Ex. - Cellular respiration, photosynthesis, digestion, protein synthesis Energy Utilization – cont. 6O 2 + C 6 H 12 O 6 6CO 2 + 6H 2 O

10 5. Organisms Respond to Stimuli Living things respond to environmental cues or stimuli. Living things respond to environmental cues or stimuli. Some stimuli are external (light and temperature), other stimuli are internal (blood glucose level). Some stimuli are external (light and temperature), other stimuli are internal (blood glucose level).

11 6. Homeostasis “internal harmony”; maintaining internal equilibrium. Involves internal feedback mechanisms that work like a thermostat Ex: pH, body temperature, water balance, etc.Ex: pH, body temperature, water balance, etc.

12 7. Evolutionary Adaptation As a group, any species can evolve, or change over time. t heir environmentLife evolves in response to interactions between organisms and t heir environment. adaptedEx. Plants in the Namibian desert have adapted to the extreme hot and dry conditions.

13 8. Universal Genetic Code The instructions for inheritance are carried by a molecule called deoxyribonucleic acid, or DNA. This genetic code, with few minor variations, determines the inherited traits of every organism on Earth.

14 B. Hierarchies of Organization As the hierarchy is explored, special qualities, called emergent properties result from the structure at each level. There are 4 major hierarchies: Biological Structure Cellular Organization Kingdoms Biological Systems

1.Biological Structure – atoms  molecules  organelles  cells. The cell is the _ basic unit _ of structure and function of all living things. In multicellular organisms, the order flows from cell  _ tissue  organ  organ system  o rganism. B. Hierarchies of Organization - cont

2. Cellular Organization – Cells can be organized as prokaryotic (without a nucleus and membrane bound organelles), or eukaryotic(with a nucleus and membrane bound organelles. B. Hierarchies of Organization - cont

3. Kingdoms – Living things are organized by their structural complexity and placed into one of six kingdoms. Archaebacteria  Eubacteria  Protista  Fungi  Plantae  Animalia B. Hierarchies of Organization - cont

4. Biological Systems – There are levels of organization beyond the individual organism. For example… organisms  populations  communities  ecosystems  biomes  biosphere.

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BASIC CHEMISTRY

Why study Chemistry in Biology? Biology - study of LIFE! Biology - study of LIFE! Chemistry - part of chemistry deals with chemical compounds…. And chemical compounds are important to living things. Chemistry - part of chemistry deals with chemical compounds…. And chemical compounds are important to living things. Ex: glucose- C 6 H 12 O 6 Ex: glucose- C 6 H 12 O 6 water - H 2 O salt - NaCl water - H 2 O salt - NaCl

Composition of Matter Matter - Everything in universe is composed of matter Matter - Everything in universe is composed of matter – Matter is anything that occupies space or has mass Mass – quantity of matter an object has Mass – quantity of matter an object has

Elements Pure substances that cannot be broken down chemically into simpler kinds of matter Pure substances that cannot be broken down chemically into simpler kinds of matter More than 100 elements (92 naturally occurring) More than 100 elements (92 naturally occurring)

99% of the mass of an organism is composed of 6 elements (SPONCH) 99% of the mass of an organism is composed of 6 elements (SPONCH) sulfur (S), sulfur (S), phosphorus (P), phosphorus (P), oxygen (O), oxygen (O), nitrogen (N), nitrogen (N), carbon (C), carbon (C), hydrogen (H) hydrogen (H) Remaining 1% is composed of trace elements required by an organism in minute amounts. Remaining 1% is composed of trace elements required by an organism in minute amounts. Iron (Fe) Iron (Fe) Iodine (I) Iodine (I) Copper (Cu) Copper (Cu) Zinc (Zn) Zinc (Zn)

Compounds Most elements do not exist by themselves Most elements do not exist by themselves Readily combine with other in a fielements xed ratio Readily combine with other in a fielements xed ratio

A compound is a substance made up of atoms of two or more elements A compound is a substance made up of atoms of two or more elements – The proportion of atoms are always fixed Chemical formula shows the kind and proportion of atoms of each element that occurs in a particular compound Chemical formula shows the kind and proportion of atoms of each element that occurs in a particular compound

Atoms in compounds are held together by chemical bonds. The tendency of elements to combine and form compounds depends on the number and arrangement of electrons in their outermost energy level - called valence electrons Atoms in compounds are held together by chemical bonds. The tendency of elements to combine and form compounds depends on the number and arrangement of electrons in their outermost energy level - called valence electrons Chemical Bonds

The chemical bonds that are important to Biology are covalent, ionic, and hydrogen bonds. The chemical bonds that are important to Biology are covalent, ionic, and hydrogen bonds.

Covalent Bonds Formed by the sharing one or more pairs of valence electrons of two atoms. Formed by the sharing one or more pairs of valence electrons of two atoms. Strongest type of bond Strongest type of bond Impt to living things Impt to living things Found in Biomolecules Found in Biomolecules Resulting substance is stable, and is referred to as a molecule. Resulting substance is stable, and is referred to as a molecule.

Ionic Bonds Formed between two atoms when one atom loses an electron, and the other atom gains an electron. Formed between two atoms when one atom loses an electron, and the other atom gains an electron. This giving & receiving results in charged particles known as ions - they have an uneven # of protons and electrons. This giving & receiving results in charged particles known as ions - they have an uneven # of protons and electrons.

Hydrogen Bonds Occurs when H+ (which is already bonded to an electronegative atom) is ATTRACTED to another electronegative atom. Occurs when H+ (which is already bonded to an electronegative atom) is ATTRACTED to another electronegative atom. Very weak bond Very weak bond Occurs between molecules, not elements. Occurs between molecules, not elements. Important in DNA, water. Important in DNA, water. Weak attraction - does NOT involve sharing or transferring of electrons. Weak attraction - does NOT involve sharing or transferring of electrons.

DNA Water