TEAS 7 Life and physical sciences

Biological hierarchy of the body

chemicals, cells, tissues, organs, organ systems, organisms

Chemicals

help build cells- macromolecules are chemicals that are essential to life

Cells

The basic unit of life

Tissues

Made up of cells that have similar structure and function

Organs

Made up of tissues that work together to carry out a specific function

Organ system

Group of organs that work together to carry out a specific function

Organism

Made up of one or multiple organs

The cell is composed of

cell membrane, cytoplasm, nucleus, Golgi apparatus, Mitochondria, lysosomes, Ribosomes, Rough endoplasmic reticulum, Smooth endoplasmic reticulum ,Vacuole

cell membrane

A cell structure that controls which substances can enter or leave the cell. (Selective permeability)

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

-Transfers material for cellular processes

Golgi apparatus

Helps packaging and processing of molecules

Lysosomes

Organelles that contain enzymes that break down molecules

-Functions in digestion and recycles old cell material

-Destroys invading bacteria as well as viruses

Mitochondria

Produces energy for the cell and converts nutrients into ATP

-

Nucelus

Part that contains cells hereditary information

-Responsible for cells growth, reproduction and function

Ribosomes

Helps synthesize proteins

-Found in cytoplasm and rough endoplasmic reticulum

Rought Endoplasmic Reticulum

Aids in packaging and transport of molecules within the cell

-ALSO SYNTHESIZES PROTEINS

Smooth Endoplasmic Reticulum

Aids in the packaging and transport of molecules, specifically lipids within the cell (No ribosomes)

-Metabolizes carbon

-Activates toxins along with harmful metabolic products

Vacoule

Stores water and other materials for the cell (Also maintains shape of cell)

Mitosis

process of cell division that results in two genetically identical daughter cells

Five main stages of the cell cycle

Interphase

Prophase

Metaphase

Anaphase

Telophase

Interphase

Is the first stage of the cell cycle. Is when the cell grows and carries out its normal functions

Prophase

Second stage of the cell cycle. The chromosomes condense and become visible. The nuclear envelope breaks down

Metaphase

Third stage, chromosomes line up in the middle of the cell

Anaphase

Fourth stage, chromosomes are pulled apart to the opposite sides of the cell. (Cell division begins)

Telophase

The fifth and final stage of mitosis, during which daughter nuclei form at the two poles of a cell. Telophase usually occurs together with cytokinesis.

-Cell divides and two daughter cells are made

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

-Produces 4 daughter cells

Meiosis stages (two cycles in this)

Prophase II, Metaphase II, Anaphase II, Telophase II

Prophase 2

sixth stage of meosis. Daughter cells contain half of the chromosomes from the original cells

Metaphase 2

Seventg stage of meiosis. The chromosomes line up in the middle of the cell again

Anaphase 2

Eight stage of meiosis. The sister chromatids are pulled apart to opposite sides of cell

Telophase 2

9th and final stage, the cells divide into four genetical diverse daughter cells also known as HAPLOIDS

Chromosomes

Long thread like structures that are round in the nucleus of the cell

-EX 46 chromosomes in every cell of the body (EXCEPT IN GAMETES)

Genes

the basic units of heredity and are made up of DNA

-Responsible for characteristics of an organism

strucutral genes

Responsible for physical traits of an organism

-COLOR OF YOUR EYES OR HAIR is determined by structural genes

Regulatory genes

Control the activity of other genes

-EX: Regulatory genes can turn other genes on or off

DNA

Made up of two long chains of nucleotides that twist to create a double helix

Four bases in nucleotides in DNA that determines proteins

GCAT

GUANINE, CYSTENINE, ADENINE, THYMINE

Base pairs

Two nucleotides that are bonded together by hydrogen bonds

AT

CG

Codon

a sequence of three nucleotides that together form a unit of genetic code for a specific amino acid in a DNA or RNA molecule.

-TOTAL OF 64 POSSIBLE CODONS

-3 of those are stop codons

RNA (ribonucleic acid)

Translates the genetic code of DNA into proteins

Differences between DNA:

-One strand

-Contains Uracil instead of thymine

Processes of RNA

transcription and translation

Transcription

Process of making RNA from DNA

RNA polymerase

Enzyme that catalyzes the formation of RNA from nucleotides. This enzyme attaches to one end of the DNA template and then moves along the template, adding nucelotides one at a time.

Three forms of RNA

mRNA, tRNA, rRNA

mRNA (messenger RNA)

RNA that carries the genetic code from the DNA in the nucelus to the ribosomes in the cytoplasm

tRNA (transfer RNA)

Helps assemble amino acids into proteins that act as adapters in the translation of the genetic sequence

Ribosomal RNA

RNA that makes up the ribosomes; clamps onto mRNA and uses its information to assemble amino acids in the correct order

Translation

Process by which mRNA is decoded and a protein is produced

How does translation happen

MRNA attaches to small subunit of ribosome and then tRNA brings amino acids to the ribosome. As the amino acids are brought to the ribosome, they are joined together by peptide bonds to form protein

-Genetic code is read in groups of three nucleotides, called codons. Each codon codes for a specific amino acid

Inhertiance (Mendels law)

Process by which traits are passed from parents to their offspring

Mendel's law of inheritance states

Two alleles for each trait. Alleles are alternative forms of a gene

one allele is dominant and the other is

recessive

Phenotype

An organism's physical appearance, or visible traits. (Usually dominant allele)

How many alleles are transferred to the offspring by parent

1 allele each

Genotype

genetic makeup of an organism

dominant trait

a genetic factor that blocks another genetic factor

recessive trait

a genetic factor that is blocked by the presence of a dominant factor

Heterozygous

An organism that has two different alleles for a trait

Homozygous

An organism that has two identical alleles for a trait

Dihybrid cross

A cross between individuals that have different alleles for the same gene

Exception to mendels law of inheritance

Incomplete dominance

Codominance

Incomplete dominance

the phenotype of the offspring is a blend of the phenotypes of the parents

Example of incomplete dominance

If a red flower (RR) is crossed with a whote flower (WW), the offspring will be pink (RW)

Codominance

Phenotype of the offspring is a combination of the phenotype of parents

Example of Codominance

If a black chicken(BB) is crossed with a white chicken (WW), the offspring will be black and white

Macromolecule's

Large molecules that are essential for the structure and function of cells

Polymer

A macromolecule that is made up of smaller units called covalent bond linked monomers

Two reactions that can occur

Dehydration and Hydrolysis

Dehydration

Synthesis is the formation of larger molecules from smaller reactants accompanied by the loss of a water molecule

Hydrolysis

The process of breaking down bonds to break monomers

What are the four major types of macromolecules

carbohydrates, lipids, proteins, nucleic acids

Carbohydrates

composed of carbon, hydrogen, and oxygen

-Known as sugars or starches

Monosaccharides

Simplest type consisting of one unit

-Cannot be hydrolyzed to make smaller units

-Glucose, fructose and galactose

Disaccharides

A double sugar, consisting of two monosaccharides joined by dehydration synthesis.

-Sucrose, lactose and maltose

Polysaccharides

Long chains of monosaccharides that are joined by covalent bonds

-Starch and cellulose

Linear Carbohydrates

Long unbranched chains of monosaccharides that form structures.

-Cellulose is a major component of rigid cell walls in plants

branched carbohydrates

Shorter chains of monosaccharides with branches.

-Maltose is a common disaccharide found in germinating seeds that are used for energy storage

Helix-Shaped carbohydrates

Coiled chains of monosaccharides that form structures.

-EX: DNA is a double helix shaped nucleic acid

Lipids

Molecule that is composed of carbon, hydrogen and oxygen

Function of lipids

Energy storage

Structure

Hormones

How are lipids formed?

By linear arrangement of carbon atoms and hydrogen atoms called fatty acid chains

Four groups of lipids

Fat molecules

Waxes

Phospholipids

Steroids

Fat molecules

Composed of glycerol molecule and three fatty acid chains

-Fats are used for long term energy storage in the body

-Cushion

Waxes

Long chain of fatty acids that are linked to long chain of alcohol

Phospholipids

Composed of glycerol molecule, two fatty acid chains and a phosphate group

Steroid

Four interconnected carbon rings. Steroids include cholesterol, which is a structural component of cell membranes and hormones like testosterone and estrogen

Proteins are composed of

carbon, hydrogen, oxygen, nitrogen , and sometimes sulfur

What are proteins made of

amino acids that are linked together by peptide bonds

What are the four groups of proteins

enzymes, structural proteins, storage proteins, transport proteins

Enzymes

proteins that can catalyze biochemical reactions without being consumed by the reaction.

-Speed up reactions by lowering energy required to initiate the reaction/

-These reactions can be exergonic(release energy) or endogenic(require energy)

Structural proteins

provide support and structure

Storage proteins

Store nutrients

Transport proteins

Transport molecules in a membrane

nucleic acids are composed of

Carbon, hydrogen, oxygen, nitrogen and phosphorus

Function of nucleic acids

store and transmit genetic information

Microorganisms

Are tiny living organisms that are too small to be seen with the naked eye and can only be seen with a microscope

Bacteria

Single celled micro-organisms that can live in many different environments. Some bacteria cause diseases such as tuberculosis, meningitis, food poisoning and more

Virus

Even smaller than bacteria and can only be seen with an electron microscope.

EX: Covid 10, measles, mumps, HIV

Protozoans

Are single celled micro-organisms that are found in water, soil and air. Some protozoans cause diseases such as malaria, giardiasis and amoebic dysentery

Fungi

Micro-organisms that are classified as eukaryotes. Some fungi are helpful, such as those used in the production of bread, cheese and beer

-Other fungi can cause disease such as athletes foot, ring worm and candidiasis

Animals

Such as parasitic worm are large enough for people to see with naked eye and live on the body. Flatworms can live in the intestines and round worms can live in the GI and lymphatic systems.