Science of Biology By: Parviz Heidari

elements of life

Organic Molecules Organic molecules are molecules composed of carbons and hydrogen, and often containing other elements such as phosphorus, sulfur, oxygen and nitrogen

the hierarchy of life

Population

Community

The Characteristics of Living Things Great Complexity & Organization Reproduction & Development Composed of Cells Mechanism for Inheritance Metabolism & Homeostasis Interaction with the environment Evolution (Adaptation)

Cellular Organization Prokaryotic cells don’t contain membrane-bound organelles Eukaryotic cells contain membrane-bound organelles

Macromolecules

Carbohydrates There are two types: The simple sugars Glucose, sucrose, fructose, … The complex carbohydrates long chains of sugars (Starches, cellulose, glycogen)

The simple sugars All carbohydrates are made up of units of sugar (also called saccharide units). Carbohydrates that contain only one sugar unit are called monosaccharides.

The simple sugars

The complex carbohydrates

Proteins

20 types of Amino acids

Proteins

Proteins

Proteins structure

Nucleic Acids

Nucleic Acids

Nucleic Acids

Bases

DNA forms

0.1 Nano = 1 Angstrom

Lipids Insoluble water Fats are a sub group of lipids Other lipids include waxes, and steroids, such as cholesterol

Fats

Saturated and unsaturated fatty acid

Cell and cell structures

Cell

Cell Division Mitosis Meiosis

Mitosis

Meiosis

Crossing over

Cell organelle

Ribosome

Cell membrane

passive and active transport

Endoplasmic Reticulum

Golgi Apparatus

Golgi Apparatus Present in most eukaryotic cells One major function is to modify, sort, and package proteins to be secreted.

Mitochondria

Mitochondria Produce the energy Pyruvate and the citric acid cycle NADH and FADH2: the electron transport chain Heat production Storage of calcium ions

Plasts

Chloroplast

Chloroplast The main role of chloroplasts is to conduct photosynthesis, where the photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water. Function Plant innate immunity Photosynthesis Energy carriers Amino acid synthesis Sugars and starches ….

Microbodies Microbodies contain enzymes that participate in the preparatory or intermediate stages of biochemical reactions within the cell. This facilitates the breakdown of fats, alcohols and amino acids. Generally microbodies are involved in detoxification of peroxides and in photo respiration in plants.

Different types of microbodies Peroxisomes break down large molecules and detoxify hazardous substances Glyoxysomes convert stored lipids into carbohydrates

Lysosomes Spherical vesicles which contain hydrolytic enzymes that can break down virtually all kinds of biomolecules

Vacuole Containing waste products Containing water in plant cells Exporting unwanted substances from the cell Maintaining an acidic internal pH

The Cell Nucleus

Genetic inheritance One chromosome from each pair is inherited from your mother and one is inherited from your father. The chromosomes contain the genes you inherit from your parents.

Gregor Johann Mendel Austrian Monk, born in what is now Czech Republic in 1822 Went to the university of Vienna, where he studied botany and learned the Scientific Method Worked with pure lines of peas for eight years In 1866 he published Experiments in Plant hybridization Work was largely ignored for 34 years, until 1900, when 3 independent botanists rediscovered Mendel’s work.

Genetics terms you need to know: Gene – a unit of heredity; a section of DNA sequence encoding a single protein Genome – the entire set of genes in an organism Alleles – two genes that occupy the same position on homologous chromosomes and that cover the same trait (like ‘flavors’ of a trait). Locus – a fixed location on a strand of DNA where a gene or one of its alleles is located.

Homozygous – having identical genes (one from each parent) for a particular characteristic. Heterozygous – having two different genes for a particular characteristic. Dominant – the allele of a gene that masks or suppresses the expression of an alternate allele; the trait appears in the heterozygous condition. Recessive – an allele that is masked by a dominant allele; does not appear in the heterozygous condition, only in homozygous.

Genotype – the genetic makeup of an organisms Phenotype – the physical appearance of an organism (Genotype + environment) Monohybrid cross: a genetic cross involving a single pair of genes (one trait); parents differ by a single trait. P = Parental generation F1 = First filial generation; offspring from a genetic cross. F2 = Second filial generation of a genetic cross

Dihybrid cross

Test cross When you have an individual with an unknown genotype, you do a test cross. Test cross: Cross with a homozygous recessive individual. For example, a plant with purple flowers can either be PP or Pp… therefore, you cross the plant with a pp (white flowers, homozygous recessive) P ?  pp

Test cross

Incomplete Dominance  Snapdragon flowers come in many colors. If you cross a red snapdragon (RR) with a white snapdragon (rr) You get PINK flowers (Rr)! R R r r  Genes show incomplete dominance when the heterozygous phenotype is intermediate. R r

Incomplete dominance R r R r When F1 generation (all pink flowers) is self pollinated, the F2 generation is 1:2:1 red, pink, white Incomplete Dominance R r R R R r r r R r

Incomplete dominance  A pink with a red?  What happens if you cross a pink with a white?  A pink with a red? 

Gene structure

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