Fase 1

Science

• Knowledge that covers general truths
or the operation of general laws,
especially when acquired and tested by
the scientific method.
• Fields of study that attempt to
comprehend the nature of the
universe.

Natural science

• Astronomy
• Biology
• Chemistry
• Earth science
• Physics

Life sciences

Biology
Anthropology
Ecology
Neuroscience
Biophysics
Biochemistry

Physical sciences

Astronomy
Geology
Physics
Chemistry
Biophysics
Biochemistry

Scientific reasoning

Knowledge
• Inductive reasoning
• Deductive reasoning

Descriptive science

• Observe
• Explore
• discover

Hypothesis-based science

• Specific question/problem
• Testable solution

Scientific method

A method of investigation involving observation and theory to test scientific hypotheses. Made by Sir Francis Bacon (1561-1626)

Testing a Hypothesis

• Testable
• Falsifiable
• Science does not claim to “prove”
anything
• openness to disproving ideas
• Experiments
• Variables
• Control groups

Basic science

To pursue science for the
sake of simply gaining knowledge

Applied science

Scientific knowledge that we can apply it to solving a specific problem or to bettering our lives

Properties of life

• Order
• Sensitivity or response to stimuli
• Reproduction
• Growth and development
• Regulation
• Homeostasis
• Energy processing

Order

Organisms are highly organized, coordinated structures that consist of one or more cells. In single-celled inside each cell, atoms comprise molecules, these in turn comprise cell organelles and other cellular inclusions. In multicellular organisms, similar cells form tissues. Tissues, in turn, collaborate to create organs (body structures with a distinct function). Organs work together to form organ systems.

Sensitivity or Response to Stimuli

Organisms respond to diverse stimuli. Movement toward a stimulus is a positive response, while movement away from a stimulus is a negative response.

Reproduction

• Single-celled organisms reproduce by first duplicating their DNA,the possibility for organisms to adapt to a changing environment.
• Multicellular organisms often produce specialized reproductive germline, gamete, oocyte, and sperm cells. After fertilization (the fusion of an oocyte and a sperm cell), a new individual develops.

When reproduction occurs, DNA containing genes are passed along to an organism’s offspring. These genes ensure that the offspring will belong to the same
species and will have similar characteristics, such as size and shape.

Adaptation

It is a consequence of evolution by natural selection. All adaptations enhance the reproductive potential of the individuals exhibiting them, including their ability to survive to reproduce. Adaptations are not constant. As an environment changes, natural selection causes the characteristics of the individuals in a population to track those changes.

Growth and development

Organisms grow and develop as a result of genes providing specific instructions that will direct cellular growth and development. This ensures that a species’ young will grow up to exhibit many of the same characteristics as its parents.

Regulation

Multiple regulatory mechanisms to coordinate internal functions,
respond to stimuli, and cope with environmental stresses.

Homeostasis

In order to function properly, cells require appropriate conditions such as proper temperature, pH, and appropriate concentration of diverse chemicals. These conditions may, however, change from one moment to the next. Organisms are able to maintain internal conditions within a narrow range almost constantly, despite environmental changes, through homeostasis

Energy processing

All organisms use a source of energy for their metabolic activities. Some organisms capture energy from the sun and convert it into chemical energy in food. Others use chemical energy in molecules they take in as food.

Evolution

The possibility for organisms to adapt to a changing environment. An organism that evolves characteristics fit for the environment will have greater reproductive success, subject to the forces of natural selection.

Organization levels

- Atom
- Molecules
- Organelles
- Cell
- Tissues
- Organs
- Organ system
- Organisms
- Population
- Community
- Ecosystem
- Biosphere

Atoms

The atom is the smallest and most fundamental unit of matter. It consists of a nucleus surrounded by electrons. Atoms form molecules.

Molecules

A molecule is a chemical structure consisting of at least two atoms held together by one or more chemical bonds.
Many molecules that are biologically important are macromolecules, large molecules that are typically formed by polymerization.

Organelles

Organelles are small structures that exist within cells. Examples of organelles include mitochondria and chloroplasts.

Cells

The cell itself is the smallest fundamental unit of structure and
function in living organisms. Some organisms consist of a single cell and others are multicellular.
Scientists classify cells as prokaryotic or eukaryotic.

Prokaryotic cells

Prokaryotes are single-celled or colonial organisms that do not have membrane-bound nuclei.

Eukaryote

The cells of eukaryotes do have membrane-bound organelles and a membrane-bound nucleus.

Tissues

Groups of similar cells carrying out similar or related functions.

Organs

Collections of tissues grouped together perfoming a common function.

Organ system

Higher level of organization that consists of functionally related organs.

Organisms

Individual living entities. (Single-cell eukaryotes and prokaryotes are also organism, usually called microorganisms)

Population

All the individuals of a species living within a specific area

Community

The sum of population inhabiting a particular area

Ecosystem

Consists of all the living things in a particular area together with the abiotic (nonliving parts of the environment)

Biosphere

The collection of all ecosystems, and it represents the zones of life on Earth. It includes land, water and even the atmosphere to a certain extent.

Taxonomy

A classification of organisms into groups based on similarities of structure or origin
- Arrangment law
- Hierarchical syste,

Linnaean system

-Domain
-Kingdom
-Phylum
-Class
-Order
-Family
-Genus
-Species
-Subspecies

Binomial nomeclature

- Genus + species

The essential elements

90% of an organism's matter is made by the essential elements (O, C, H and N) which are rare in nonliving stuff

Inorganic compounds

Substance that lacks carbon–hydrogen bonds
- Many contain H
- Few contain

Essential for life are: Water, salts, acids and bases

Water and it's properties

It makes up about 60-70% of adults' body weight, it is found within and between the cells
Water properties:
- Polarity
- Different matter states
- High heat capacity
- Vaporization
- Is a solvent
- Cohesiveness and adhesiveness

Water polarity

One of water’s important properties is that it is composed of polar molecules: the hydrogen and oxygen within water molecules
(H2O) form polar covalent bonds.
We call a polar substance that interacts readily with or dissolves in water hydrophilic. In contrast, nonpolar molecules such as oils and fats do not interact well with water, we call such nonpolar compounds hydrophobic.

Water's states

As water molecules make hydrogen bonds with each other, water takes on some unique chemical characteristics compared to other
liquids. In liquid water, hydrogen bonds constantly form and break as the water molecules slide past each other. When the heat rises as water boils,
the water molecules' higher kinetic energy causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas (steam or water vapor). Alternatively, when water temperature reduces and water freezes, the water molecules form a crystalline structure maintained by hydrogen bonding.

Water's high heat capacity

Water’s high heat capacity is a property that hydrogen bonding among water molecules causes. We define specific heat as the amount of heat one gram of a substance must absorb or lose to
change its temperature by one degree Celsius. For water, this amount is one calorie.

Water's heat of vaporization

Water also has a high heat of vaporization, the amount of energy required to change one gram of a liquid substance to a gas.

Water's solvent properties

Since water is a polar molecule with slightly positive and slightly negative charges, ions and polar molecules can readily dissolve
in it. Therefore, we refer to water as a solvent.

Water’s Cohesive and Adhesive Properties

In cohesion, water molecules are attracted to each other (because of hydrogen bonding), keeping the molecules together at the liquid-gas (water-air) interface, although there is no more room in the glass. Cohesion allows for surface tension.
These cohesive forces are related to water’s property of adhesion, or the attraction between water molecules and other
molecules.

pH

The pH of a solution indicates its acidity or basicity. The pH test measures hydrogen ions' concentration in a given solution.

Acid

A substance that increases hydrogen ions' (H+) concentration in a solution, usually by having one of its hydrogen atoms dissociate.

Base

A base provides either hydroxide ions (OH–) or other negatively charged ions that combine with hydrogen ions, reducing their concentration in the solution and thereby raising the pH.

pH scale

The pH scale is, as we previously mentioned, an inverse logarithm and ranges from 0 to 14. Anything below 7.0 is acidic, and anything above 7.0 is alkaline. Extremes in pH in either direction from
7.0 are usually inhospitable to life.

Biomolecules

These molecules always contain carbon
Four main groups:
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids

Biomolecules: dehydration

Bonds are formed and energy is required

Biomolecules: Hydrolysis

H2O breaks a covalent bond and energy is releases. Enzymes speed up these processes.

Carbohydrates

They consist entirely of carbons and hydrogen.
These are found in grains, fruits, and vegetables
• Keyword: ENERGY

Types of carbohydrates

Monosaccharide: Single sugar (simple sugars)
Disaccharide: Two sugar molecules linked
Polysaccharide: Many sugar molecules linked

Lipids

They are non-polar
• Hydrophobic = Insulation
• Long-term use energy

Building blocks
• Hormones
• Cellular membranes

Are divided in fats, oils, waxes, phospholipids,
steroids

Proteins

These are the most structurally diverse and the most functionally diverse biomolecules
Enzymes:
• Breakdown.
• Rearrangement.
• Synthesis.
Hormones:
• Regulation.

Nucleic acids

The most important macromolecules, it is the cell's blueprint
- DNA
- RNA

Nucleotides

1. Nitrogenous base
2. Pentose
3. Phosphate group

Nitrogenous bases

• (A)denine
• (G)uanine
• (C)ytosine
• (T)hymine
• DNA only
• (U)racil
• RNA only

DNA double-helix structure

Each pair of nitrgenous bases is binded by hydrogen bonds. Strands hold antiparallel orientation

RNA

Single-stranded (usually)
• Ribonucleotides
• Ribose
• A nitrogenous base
• Phosphate group

The Central Dogma of Life

Transcription:
• DNA dictates the structure of mRNA.
Translation:
• RNA dictates the protein's structure.