DP1 Biology Review (WIP)

prebiotic

before life

Cells

Basic unit of life: carry out Metabolism, Growth, Reproduction, Homeostasis, Nutrition, Excretion, and Response

Cell Theory

• cells are t he smallest unit of structure and function in living things

• All living organisms are made of one (or more) cell

• All cells come from pre-existing cells

Miller Urey Experiment

An experiment that found that organic molecules can form in a strongly reducing atmosphere.

Monomer

small chemical unit that makes up a polymer

Polymer

larger molecules made up of monomers

What are the hypothesized steps to the first cell?

1. Creation of Simple Organic (carbon-based) Compounds (synthesis)

2. Creation of More Complex Organic (carbon-based) Compounds (polymerization)

3. Creation if Polymers that can Self-Replicate (self-replication)

4. Spontaneous Formation of Membranes (compartmentalization)

RNA World

The theory that RNA was the firs form of genetic material because it can self-replicate and has some catalytic activity. RNA -> RNA -> protein

Central Dogma

theory that states that, in cells, information only flows from DNA to RNA to proteins

Aqueous

watery solvent

hydrophilic

water loving

hydrophobic

hates water

LUCA (Last Universal Common Ancestor)

The first ever organism from which every living being has originated. Supported by the fact that the same/similar genes are seen in all organisms + same genetic material to make it (nitrogenous bases).

Hydrothermal Vents

spots on the ocean floor where hot gases and minerals escape from earth's interior into the water

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

Cytoplasm

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

Cell Membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell made of multiple components

Prokaryotic

An organism whose cells do not have an enclosed nucleus, such as bacteria.

Eukaryotic

A cell characterized by the presence of a nucleus and other membrane-bound organelles. Eukaryotes can be unicellular (protists) or multicellular (fungi, plants and animals).

unicellular

an organsim consisting of only one cell

Multicellular

An organism that contains more than one cell

cell wall

rigid structure outside the cell membrane responisble for structural support of the cell

Plasma Membrane/Cell membrane

Flexible structure that regulates materials in and out of the cell

Cytoplasm

Gel-like fluid where chemical/metabolic reactions take place which is full of molecules and ezymes

Plasmids

small pieces of PDA seoerate from the nucleoid region that allows for variation in prokaryotes

70S ribosomes

small structure made of RNA and protein that helps the cell translate the genetic information into amino acids

Capsule

Covers the cell wall in prokaryotes.

Pili

short, hairlike protein structures on the surface of some bacteria

Bacterial Flagellum

A ropelike structure built from actin proteins that, through rotary movements, propels a bacterium through fluid.

Nucleoid

A dense region of DNA in a prokaryotic cell.

plant cells

have chloroplasts and a cell wall

animal cells

1) lacks cell wall 2) lacks chloroplasts 3) lacks large central vacuole

Nucleus

controls and regulates the activities of the cell and carries the genes, structures that contain the hereditary information

Mitochondria

responsible for ATP/energy production via the process of aerobic cell respiration

80S ribosomes

a two part structure responsible for deliverig + modifying proteins (creating them) from RNA

Endoplasmic Reticulum

A membrane network within the cell that synthesizes and transports protein or lipids

Golgi Apparatus

a series of stacked membranes that are located within the cytoplasm, which modifies and stores proteins, forms lysosomes, and transports vesicles of proteins from the ER. Proteins enter unmodified and able to touch cytoplasm, leave in vesicles

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement. Is located on the inside of a cell.

Lysosomes

responsible for the digestion of macromolecules, old cell parts, and microorganisms. Specific enzymes in the lysosome degrade substances at a pH that is not seen in the cytoplasm. Containing these enzymes also means that they won't go about digesting the entire cell and will work faster due to being in close proximity with their respective substances. Are transported to the lysosome via a vesicle

Vacuole

a single membrane with no definite shape or size. Usually filled with fluid. Found in both prokaryotic and Eukaryotic cells. It can help with water balance, holding waste, etc.

Chloroplast

An organelle responsible for photosynthesis (converting linght energy to chemical) found in plants and algae

Centrioles

These barrel-shaped structures are used to help cells during division. Animal cells only.

nuclear envelope

layer of two membranes that surrounds the nucleus of a cell, allows for DNA processes to happen separate from the rest of the cell and has pores small enough to only let RNA out. During cell division, the nuclear membrane separates into vesicles before combining again

chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell

Vescicle

Moves proteins, lipids and carbohydrate particles through the cell, from the endoplasmic reticulum to golgi, towards the cell membrane where contents are secreted

Atypical eukaryotic cells

Do not contain, or contain abnormal numbers of the cell structures and organelles that are found in most other eukaryotic cells.

Magnification Calculations

image size over actual size (IAM triangle)

1cm or 10mm is equivalent to

10000Mm and 10000000nm

Endosymbiosis process

1. Start with two independent bacteria

2. One bacterium engulfs the other

3. One bacterium now lives inside the other

4. Both bacteria benefit from the arrangement

5. The internal bacteria are passed on from generation to generation

endosymbiotic theory

theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms

double membrane-bound organelles

part of the endosymbiotic theory that two systems ca live independently of one another and then come together to live in the same organism, maintaining their membrane.

Viruses

tiny particles, smaller than bacteria and other pathogens, which must invade living cells in order to reproduce; when they invade, the cells are damaged or destroyed in the process, releasing new particles to infect other cells. They are small and fixed, have genetic material, have a capsid made of protein, no cytoplasm, and have hardly any enzymes, not really considered living.

acellular virus

use host cell's metabolic processes

Nucleic Acid genetic material

makes up DNA and RNA which is the genetic material that codes for genes

Capsid

Outer protein coat of a virus

Enzymes

a catalyctic globular protein that speeds up the rate of specific chemical reactions without being consumed on the process

RNA

a single-stranded nucleic acid that contains ribose instead of deoxyribose, also rumored to have been part of the 4-step process to the introduction of life because it can self-replicate. Also used in DNA replication.

genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

Lytic Cycle

DNA is pumped into a cell so that the cell mindlessly recreates the virus until it ruptures.

Lysogenic Cycle

the cell integrates the virus DNA with its own DNA and replicates containing that DNA. This can go unnoticed until the process is activated by a specific environment where it then goes into the Lytic Cycle and eventually ruptures.

obligate parasites

organized semi-life forms that cannot live without a host

Escaped genes/Progressive hypothesis

The theory that viruses originated from one virus, which was an escape of modified cellular components (including pieces of DNA).

Regression hypothesis

The Regression theory concludes that viruses used to be cells that lost organistic functions and organelles, becoming parasitic.

Multiple origin virus theory

The theory that viruses originated from different origins die to the various shapes they have but have similar features for survival

translation

The process by which mRNA is decoded by a ribosome (rRNA) and a protein is produced using free-roaming amino acids in the cytoplasm

Convergent Evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments for means of survival.

What conditions made early Earth inhospitable to life?

lack of an atmosphere, water-less, not enough oxygen, meteor showers often, too hot, no ozone layer

What types of polymers might have been synthesized for use in protocells?

proteins, lipids, nucleic acids, carbohydrates

Protocell

a large, ordered structure, enclosed by a membrane, that carries out some life activities, such as growth and division, came before LUCA and was a part of the process of achieving LUCA

What does LUCA stand for?

Last Universal Common Ancestor

What evidence do we have that today's diverse life forms evolved from a universal common ancestor?

universal genetic coding and identical DNA replicating processes

Synthesis

Simple organic molecules were made from the inorganic molecules on early earth

Polymerization

These simple molecules (monomers) were able to be built into more complex molecules (polymers) compounds like cellulose in t he cell wall and nucleic acids

Self-replication

These molectules have the ability to be replicated in the new cells and the compounds are essentially inherited

Compartmentalization

The spontaneous arrangement of fatty acids in water allows for organization and an internal environment to the different than the external (protocells)

Unity and Diversity in Cells

In order for LUCA to be the first common ancestor (and the successfully surviving one) many other versions of it have existed but died off due to natural selection. In order to fit into all kinds of environments, LUCA adapted itself by changing its characteristics, thus creating diversity.

organelles

A tiny cell structure that carries out a specific function within the cell

Form=function

The idea that the structure of an organelle loosely determines the role that it plays in the body

Compartmentalization in the cytoplasm

A cell contains multiple membrane-bound organelles for the purpose of division of labor

Cell Fractionation

technique in which cells are broken into pieces and the different cell parts are separated, specifically looking at the rupture of membranes and how they rearrange themselves

Clathrin

protein that coats the plasma membrane's inward-facing surface and assists in forming specialized structures, like vesicles. Compounds bind to clathrins to make the membrane pinch inwards

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane creating a vesicle of outside substances in the cell

Receptor-Mediated Endocytosis

The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with clathrins specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.

Exocytosis

Process by which a cell releases large amounts of material through a vesicle reaching the membrane

Outer membrane of mitochondria/chloroplast

separates the contents of the mitochondrion from the rest of the cell: protection

Matrix

Cytoplasm-like substance containing enzymes and reactants specific to mitochondrial metabolic reactions

Small Intermembrane Space

Very small volume of space between the inner and outer membranes; collects proton (H+) gradient, which allows for homeostasis and ATP production (diffusion of H+) through ATP synthase in the membrane.

Folded Inner Mitochondrial Membrane

Folds called cristae contain enzymes and other proteins required for cellular respiration reactions and have a larger surface area to encourage more cellular respiration processes.

Stroma

Cytoplasm-like substance containing enzymes and reactants for specific chloroplasmic reactions like light independent reactions

Small Thylakoid Space (Lumen)

Very small volume of space inside of thylakoid sacs; collects proton (H+) gradient which helps maintain homeostasis and encourages ATP generation

Extensive Thylakoid Membranes

Thylakoid membranes contain photosystems and other proteins and enzymes required for photosynthesis reactions seen through the large surface area of the granum to encourage more photosynthesis reactions

Granum

Stacks of thylakoids meant to capture light

Thylakoid

a singular stack in a granum made of an inner membrane containing chlorophyll

Rough Endoplasmic Reticulum

contains ribosomes attached to the surface of the membrane that create proteins for secretion (leaving the cell by going to the golgi and then through exocytosis)

Phospholipids

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group that makes up a membrane in cells and organelles. Is formed by removing a fatty acid from the glycerol and instead adding a phosphate in that spot.

amphipathic

having both polar (hydrophilic) and nonpolar (hydrophobic) properties

integral proteins

Proteins that go through the phospholipid bilayer (typically trasport proteins)

peripheral proteins

proteins that are bound to the surface of the membrane

Channel protein

A membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel. Usually has a gate at the entrance that is opened with a voltage change

Carrier protein

A membrane protein, specifically a transport protein, that holds onto molecules and shuttles them across the membrane. Opens when neurotransmitters bind to it, causing it to change shape and open.