BIOLOGY NMAT (Part 1)

Characteristic of Life

Characteristic of Life

All lives are well organized

Energy Use

All lives need energy to support

Reproduction

All lives should be able to reproduce itself

Growth

All lives grow and develop

Response to Stimuli

All lives can respond to internal or external stimuli

Homeostasis

All lives have the ability to maintain a relatively stable internal environment — self-regulation

Cell Theory

• Cell is the building unit of all living organisms.

• All cells come from pre-existing cells.

• All metabolism occurs in body cells; cells are the functional unit for all lives.

Gene Theory

• All genetic information is stored in DNA – genes

• Genes control most, if not every, aspect of an organism.

• The DNA language can be transcribed into RNA language and then translated into protein language for its final function

Purpose of Homeostasis

to ensure proper function of the body

Atom

consists of a central nucleus surrounded by one or more negatively charged electrons.

3 Components of Atoms

electrons, neutrons, and protons

Electrons

a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids; both energy and substance particles

Neutrons

A subatomic particle of about the same mass as a proton but without an electric charge is present in all atomic nuclei except those of ordinary hydrogen.

Protons

A stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.

Molecules

• Formed by atoms

• Joined by chemical bonds

• molecular formula and structure formula

Ion Bond

forms when atoms lose or gain electrons

Covalent Bond

form when atoms share electrons, and very strong bonds. The major organ in organic chemicals.

Hydrogen Bond

 Weak electrical attraction between the positive end of one molecule and the negative end of another.

Buffers

 Solutions that resist change in pH solutions upon adding small amounts of acid or base.

pH

Represents the concentration of hydrogen ions [H+] in solution.

Nucleus

• the control center

• Holds all of the cell’s genetic information

• Makes decisions about cell needs

Ribosome

• the factory

• Synthesizes proteins

Rough Endoplasmic Reticulum

Edits and finalizes proteins made by ribosomes.

Smooth Endoplasmic Reticulum

Synthesizes carbohydrates and lipids.

Golgi Apparatus

• The post office

• Tags and ships packages to their destinations

Mitochondria

• the powerhouse

• Produces ATP for the cell’s activities

Lysosome

• the recycling center

• Recycles waste and foreign bacteria

Cell Membrane

•  lipid bilayer which envelops the cell.

• For Protection, Communication, and Selective Exchange

Passive Transport

• Does not use energy

• Osmosis, diffusion, facilitated diffusion

• Natural movement from high concentration to low concentration

Active Transport

• uses energy

• Movement from against natural diffusion

Prokaryotes

• Examples: bacteria, microscopic organisms

• Structure: DNA, ribosomes, and cell membranes.

• Except for ribosomes, prokaryotes DO NOT have organelles

Eukaryotes

• Animals: with organelles and cell membranes

• Plants: with organelles and cell membranes like animal cells, but also have chloroplasts and cell walls.

Glycolysis in aerobic Respiration:

• Glucose is broken down into pyruvate.

• 2 ATP produced

Krebs Cycle

• Acetyl CoA (made from pyruvate) runs a cycle of reactions, regenerating at the end of each cycle.

• All of the electrons are passed to NADH and FADH2 (electron carriers).

• 2 ATP produced.

Oxidative Phosphorylation

• 32 ATP produced

Glycolysis in Anaerobic Respiration

• Glucose is broken down into pyruvate;

• 2 ATP produced.

Fermentation

• Pyruvate is broken down into ethanol or lactic acid.

• Glycolysis intermediates are produced to allow glycolysis to begin again immediately.

Chloroplasts

An organelle in plant cells where photosynthesis occur.

Photophosphorylation

 a process that ATP is generated via light reactions in photosynthesis.

Light Reaction

The first phase of photosynthesis which light is harvested and the electron transfer occurs, ATP, NADPH and oxygen is generated.

Dark Reaction

The second phase of photosynthesis where carbon dioxide is fixed and carbohydrates are generated by consuming ATP and NADPH.

Chloroplasts

These are organelles which allow the organism to perform photosynthesis, obtaining energy from sunlight.

Chlorophyll

Proteins found in chloroplasts which have the ability to absorb sunlight for photosynthesis.

Prophase

• Chromosomes condense and become visible.

• Nuclear envelope breaks down.

• Centrioles take positions on opposite sides of nucleus.

Metaphase

• Chromosomes line up single-file in the middle of the cell.

• Spindle fibers from the centrioles attach to each side of the centromeres of the chromosomes.

Anaphase

• Sister chromatids are pulled apart to become individual chromosomes.

• Chromosomes move until they reach centrioles on opposite sides of the cell.

Telophase

• Chromosomes dissolve.

• Nuclear envelopes re-form around both sets of chromosomes.

Ecology

The study of organisms and environment

Biosphere

• The entire portion of the earth is inhabited by life.

• The sum of all the planet’s ecosystems.

Biomes

The world’s major communities classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment.

Community

A group of populations living in the same area.

Population

 A group of individuals in a particular geographic area that belong the same species.

Producers

They are primarily green plants that bring energy into the system by capturing sunlight.

Consumers

An organism in an eco system that lives by eating other organisms.

Food Web

A complex interaction of feeding relationships.

Chemical Cycling

Nature’s way of allowing life on Earth access to limited resources by continually transferring the energy from one form to the next.

Primary Succession

An event in which life begins to exist where no life existed previously.

Secondary Succession

The change in composition of the species which live in an area.

Aquatic Ecosystems

 Most of life on Earth lives in the oceans, a poorly understand system of oceans, lakes, streams, rivers, and estuaries.

Terrestrial Biomes

The group of ecosystems which share the same climate, flora, and fauna.

Population Density

 Individuals per unit area or volume.

Dispersion

 The pattern of spacing for individuals within the boundaries of the population.

Reforestation

It is the development of a forest in a deforested area to ensure a sustained yield.

Conservation

 It is the safeguarding, maintaining or protecting and wise management of natural resources.

Resources

Materials which satisfy human needs and want in a given space and time, and serve to attain individual as well as social welfare.

Non Renewable Resources

 There is no known process by which they can be renewed quickly. They are available in fixed quantities and too much exploitation would mean their end. Ex: Minerals, ground water.

Chromosome

where the cell nucleus pack its long stretch of DNA molecule into, it is the functional unit for heredity

Meiosis

• A reproductive process which produces two unique haploid cells from one cell.

• These unique haploid cells are gametes, sex cells for reproduction.

Haploid

Descibing a cell which has one entire set of the oganism’s chromosomes.

Diploid

 Describing a cell which has two entire sets of the organism’s chromosomes.

Cross

The parents which reproduce together.

Dominant/Recessive

If present, the dominant allele appears in the phenotype

Co-Dominance

Both dominant alleles show up in the phenotype

Incomplete Dominance

The phenotype is the middle of the two alleles.

Polygenic Traits

Many genes (with 2 alleles each) combine to create one physical trait.

DNA

• Is the cellular genetic material

• It contains two strands based on base pairing between A and T, C and G.

• The two strands are anti-parallel and form double-helix structure

mRNA

Copies information from DNA through base paring mechanism

tRNA

carries amino acids to protein synthesis sites

rRNA

component for ribosome

ncRNA

regulate cellular processes

The Central Dogma

DNA → RNA → Protein

Transcription

•  RNA polymerase reads DNA and produces pre-mRNA.

• The pre-mRNA is edited via splicing of exons together to form the mature mRNA which leaves the nucleus to enter the cytoplasm.

Translation

Ribosomes read the mRNA script and tRNA’s bring amino acids in order to produce the final gene product, proteins.

Causes of Mutation

• Errors during DNA replication

• DNA damage

• Chromosome errors

Autosomal Chromosomes

Chromosomes that code for the regular human traits.

Sex chromosomes

It determines biological sex by triggering the development of male or female sex characteristics.

Genetic Disorder

A disease or sickness caused by DNA at birth.

Heritable Adaptation

Any inherited trait that ultimately leads to a reproductive advantage of a species.

Punctuated Equilibrium

Evolutionary changes occur relatively quickly followed by long periods of stabilization.

Natural Selection

• is a result of a species interaction with the environment, with “selection” being determined by whichever species lives long enough to propagate and thereby be successful.

• Survival of the “Fittest”.

• Fit refers to best fit to environment.

Precambrian Time

• 99% of Earth’s History

• All of the life history events above happened during this time.

• Oxygenation of the atmosphere, the first life forms, etc. All life was aquatic

Paleozoic Era

• The first invertebrates and vertebrates.

• Insects, plants, and reptiles appeared.

• First movement of organisms onto land.

Mesozoic Era

• “The Age of Reptiles.”

• Reptiles became dominant.

• Mammals appeared.

• Dinosaurs became extinct.

Cenozoic Era

• “The Age of Mammals.”

• Mammals became dominant.

• Glaciers melted.

• The climate warmed.

• Humans appeared

Taxonomy

The discipline of studying and classifying organisms.

Animalia

A kingdom that includes heterotrophic consumers

• herbivores → eat only plants

• carnivores → eat only animals

• omnivores → eat only plants and animals

• detritivores → eat dead and decaying organic matter

Binomial Nomenclature

A standard way to refer to the scientific name of an organism by using the genus and species.

Phylogeny

The process of classifying and organizing organisms based on evolutionary relationships

Bacteria

smallest and simplest organisms, scientifically called prokaryotes.

Binary Fission

Asexual reproduction of prokaryotes.