General Bio I Lecture 4 (Part 1)

Robert Hooke

In 1665, identified small box compartments in a homemade microscope and named them cells based off of monks

Anton van Leeuwenhoek

Bult more than 250 microscopes that could magnify up to 300 times. Identified microbial life through teeth plaque and named them animalcules

Cell Theory

All living things are composed of cells, Cells are the basic unit of life, every organism or living thing consists of 1 or more cells

Microscope Importance

Allows scientist to cell size, shape, organization, and internal structure. 1mm = 1,000um = 1,000,000 nm

Studying Cells Medical Relevance

Doctors can identify diseases based on cells shape and function (biopsies, papsmears, blood tests, microscopy and staining)

Prokaryotes

Cells that are unicellular, lack nucleus, and lack membrane bound organelles

Bacteria

Prokaryotic cells, small size allows them to adapt and occupy every environment. Most found on skin and intestinal tract and minimal cause disease. Produce vitamin K and B (aid in peptide creation to increase moods)

Lactic Acid

Turns sugar from fibers into short fatty acids used in producing ATP and NADH (enzyme for cellular respiration and energy production)

Why bacteria are successful

• Long evolutionary history

• small size allows them to occupy a variety of environments

• They have many sources of energy (light, organic and inorganic compounds)

• They have rapid reproduction rates and genetic variation

Spherical (Cocci)

Identify the processes of pathogens in the human body (STD, Gonorrhea)

Rod (Bacilli)

Can cause a variety of diseases and decomposition (Fermentation, E.coli)

Spiral

Many cause diseases and take part in nutrient cycling (Syphilis, Lyme disease)

Antibiotics

Target structure unique to bacteria (cell wall, ribosomes, DNA enzymes). These targets cannot be found in human cells or viral infections

Archaea

Prokaryotic cell, though they look like bacteria they have unique membrane molecules, genetic sequence and enzymes. Usually live in extreme environments

Pyrococcus furiosus

Live in extremely high temperatures and has the ability to copy DNA with high validity

Halobacterium salinarum

Live in high salt concertation environments. Accumulates a high concentration of salt into potassium and chloride ions into its cytoplasm to balance out the oceans pressure

Methanobacterium

The first discovered. lives in an oxygen-free environment and produces methane as a byproduct

Cell Necessities

All cells need organelles that contain DNA, RNA, ribosomes, cytoplasm and a cell membrane. chemical reactions such as cellular respiration and protein synthesis that are needed to sustain life

Eukaryotes

Are unicellular or multicellular, have a nucleus and contain membrane bound organelles. Divide tasks into specialized compartments

Organelles

Are enclosed internal compartment in a Eucaryotic cell that perform specific functions for the cell’s survival and to reach homeostasis

Nucleus

Contains the majority of a cell’s DNA that aids in protein synthesis. It is surrounded by a nuclear envelope (double membrane) that has nuclear pores.

What do Nuclear Pores do?

They control what comes in and out of the nucleus. mRNA exits through these pores after experiencing synthesization

Nucleolus

Is a dense region inside the nucleus. it contains the genes for ribosomal RNA which is used to reduce ribosomes

Life’s Central Dogma

The explanation for how genetic information is stored, transported, and expressed

Cancer Diagnosis

Doctors examine the changes that occur to a cell’s membrane and nucleus

Eukarya

Eukaryotic cells that are found in animals, plants, fungi, and protists.

Biological Membranes

Physical barriers made with phospholipid bilayer that are buolt based off of:

• hydrophobic interactions with the nonpolar fatty acid tails of phospholipids (interior)

• hydrophilic interactions of the polar heads of phospholipids and water molecules (surface)

Selective Permability

The hydrophobic core allows for small nonpolar molecules to pass rapidly. Small polar molecules (ions) may diffuse at a slower rate due to their charge. Molecules that are large and too polar (glucose, amino acids) cannot be pushed with diffusion.

Fluid Mosaic Models

Membranes are not only made with phospholipids they also contain proteins, glycoproteins, glycolipids, and cholesterol. The molecules are able to move freely allowing the membrane to adapt, repair, and interacting with the environment easily

Diffusion

The spontaneous movement of molecules from an area with higher concentration to an area with lower concentration to reach equilibrium. This action is done passively without the use of ATP or the help of transportation proteins

Concentration gradient

When the concentration of solutes is higher in one area compared to the other causing diffusion and osmosis

Facilitated Diffusion

A passive (no ATP) method that helps substances that cannot cross the membrane effectively overcome the membrane barrier with the help of carrier proteins moving them down the concertation gradient

Aquaporins

Water transporting proteins that act as a funnel to bring water in and out of the cell rapidly

Osmosis

The passive movement of water molecules across a membrane to an environment with less water and more solute (dissolvable substance) to reach equilibrium

Hypertonic

There is a high presence of solute on the outside if the cell causing water to leave the cell making it shrink and shrivel

Isotonic

There is an equal amount of solute present inside and outside the cell causing water to move in an out at an equal rate letting the cell stay the same size

Hypotonic

Less solute present outside the cell causing water to enter the cell making it reach a point of combustion or swelling

Active Transportation

An ATP powered method that uses transportation proteins to move substances against the concertation gradient

Phosphorylation Reaction

Method that uses ATP powered transport proteins to move substances against the concentration gradient. This move is made easier since the phosphate group, carries negative charge attaches to the protein changing its shape

Exocystosis

The movement of a large molecule or amounts of molecules from the inside to the outside of the cell. Are pushed by proteins and are held in vesicles (phospholipids) that attach to the cell membrane

Endocytosis

The action of the cell membrane folding inwards to bring in a large molecule or amounts into the cell with the formation of a pocket called a vesicle (phospholipids)

Chlamydia

Has an elementary body (infectious form) that enters host cells in the vaginal tract with endocytosis. The elementary body replicated within host cell which protects them from white blood cell. These replicas exit through exocytosis to continue the spread

Viral Infections

Infection that enters the cell through endocytosis and reproduces within host cell until it bursts or exist through exocytosis to continue spreading