Unit 1 Bio

Hydrogen bonds happen when ___.

a partial positive end of one molecular bond attracts the partial negative end of another molecular bond in space

What is the term for a bond in which two atoms share a pair of electrons?

Covalent bond

Eukaryotic cells can trigger the release of material from secretory vesicles to the extracellular space using a process called exocytosis. What is an example of materials commonly released this way?

hormones.

Evaluate the importance of the endoplasmic reticulum in the synthesis, modification, and transport of cellular proteins.

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The endoplasmic reticulum plays a crucial role in protein synthesis, modification, and transport.

Functional ribosomes in eukaryotic animal cells are located in 1) free in the cytoplasm, 2) attached to Rough ER and 3) ________.

in the mitocondria

Imagine a scenario where the cell's mitochondria are dysfunctional. How might this impact the overall functioning of the cell?

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The cell’s ability to produce energy in the form of ATP would be impaired.

In which type of cell would you expect to find an abundance of mitochondria?

Heart cell

How do peroxisomes contribute to cellular function?

Breakdown of fatty acids and detoxification

Which of the following organelles has both an outer and an inner membrane?

mitochondrion

All of the following, except one, are evidence that support the endosymbiosis theory.  \n Which **one does not support** the endosymbiosis theory?

Mitochondria and chloroplasts have the same number of genes as most bacterial cells.

Some ribosomes get transported to the rough endoplasmic reticulum.  When the new protein is just beginning to be made, these ribosomes have a 20-24 amino-acid segment, called the ER signal sequence, that corresponds to the N-terminus of the premature protein.  What grabs the ER signal sequence and shuttles the ribosome to the translocon in the membrane of the rough endoplasmic reticulum?

Signal recognition particle (SRP)

Discuss the role of the nucleus in controlling cellular activities and hereditary information.

The nucleus contains genetic material and controls cell functions by directing protein synthesis.

Which of the following would you expect to find in a cytosolic fraction prepared from cultured mammalian cells?

ribosomal subunits

Cells that are specialized for the secretion of proteins are likely to have which of the following features?

enlarged endoplasmic reticulum

Which of the following best describes the role of the lysosome?

clean up, recycling, and disposal of macromolecules

What organelle makes fats, phospholipids, and steroids?

Smooth endoplasmic reticulum

What are the small, membrane-bound organelles that provide a safe place within the cell to carry out biochemical reactions that generate and remove harmful, highly reactive oxygen species like superoxide and hydrogen peroxide?

Peroxisomes

Prokaryotic cells do not possess

a nucleus.

Which organelle is responsible for modifying, sorting, and packaging proteins for transport?

Golgi apparatus

What is the primary function of the smooth endoplasmic reticulum?

Lipid synthesis and detoxification

Mitochondria contain their own genome, can duplicate, and divide on a different time line from the rest of the cell. Nevertheless, mitochondria cannot function for long when isolated from the cell because they are

endosymbionts.

A certain type of cell has an unusually high number of ribosomes. What might be the primary function of this cell?

Protein synthesis

The cell constantly exchanges materials by bringing nutrients in from the external environment and shuttling unwanted by-products back out. Which term describes the process by which external materials are captured inside transport vesicles and brought into the cell?

endocytosis

The nucleus, an organelle found in eukaryotic cells, confines the __________, keeping them separated from other components of the cell.

chromosomes

A cell is actively producing a large amount of lipids. Which organelle is likely to be highly active in this process?

Smooth endoplasmic reticulum

What organelle receives the freshly made proteins that are destined for secretion out of the cell?

Rough endoplasmic reticulum

Organic molecules

Chemical compounds that contain carbon and hydrogen

Inorganic molecules

Not composed of carbon atoms

Condensation reaction

In which a covalent bond is formed between two molecules as water is expelled used to build polymers

Hydrolysis

Involves cleavage of a covalent bond with the accompanying consumption of water

Fatty acid molecule

Consists of carboxylic acid attached to a long hydrocarbon change.

Lipid

AN organic molecule that is insoluble in water but dissolves readily in nonpolar organic solvents

Phospholipids

Contain two hydrophobic fatty acid tails and a hydrophilic head.

Amino acids

Small organic molecules containing both an amino group and a carboxyl group.

Nucleotides

Basic building block of the nucleic acids

Covalent bonds

Formed by sharing of electrons, are broken by enzyme catalysis that is specific for a protein and its substrate.

Ionic bond

Is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, Complete transfer of valence electrons

Hydrogen bond

A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other..

Bonds in the order of strength

1\.Ionic

2\.Covalent

3\.Hydrogen

Macromolecules Polymer

built from covalently linked subunits include proteins, nucleic acids, polysaccharides with a molecular mass greater than a few thousand Daltons.

Monomer

Small molecule that can be linked to others of a similar type to form a larger molecule

Hydrolysis

The addition of water, A molecule of water breaks one or more chemical bonds.

Chromosome

A DNA molecule circular, linear, proteins bind to DNA.

Ribosomes

Consists of RNA, and proteins, site of protein synthesis. Links amino acids together.

Organelle

Any membrane bound compartment inside a cell.

Cytoskeleton

Rod like proteins inside that function in structural support, transport materials, movement in some species

\-Made of amino acid chains forming protein subunits

Cell Wall

Stiff stricture outside the cell membrane composed of carbs.

Flagellum

Long flexible structure that extends from the cell whips and rotates.

Nucleus

Unique to eukaryotes enclosed by a double membrane, cells chromosomes.

\-Largest Organelle

\-Encoded with genetic instructions for creating proteins

\-Openings called pore complexes in the nuclear envelope for exchange of molecules

Mitochondrion

Found in Eukaryotes burns sugars to provide energy. produces chemical energy known as ATP that’s required for metabolism.

\-ATP is generated by a process called oxidative phosphorylation

\-Nutrients provide high energy electrons which are used to pump protons from the matrix to the intermembrane space.

Eukaryote

A lineage of species with cells that contain a nucleus and mitochondria.

\-Enclosed within two concentric membranes which form the nuclear envelope

\-Largest organelle

\-Encoded with genetic instructions for creating proteins

\-Openings called pore complexes in the nuclear envelope for exchange of molecules

Prokaryotic

Lineage Archaea and bacteria, with cell that lack a nucleus.

Vacuole

stores key molecules, very prominent in most plant cells.

Chloroplasts

Contains the molecular machinery required for photosynthesis.

\-Green organelles found in plants and algae

\-2 surrounding membranes containing chlorophyll.

\-Produces ATP

\-Releases oxygen as a byproduct

\-Contain their own DNA and are thought to have evolved from bacteria

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Endoplasmic Reticulum

Forms a branching network of narrow tubes and flattened sacs.

\-Enclosed sacs are called Cisternae

\-Storage site for calcium

\-Responsible for Lipid synthesis

Smooth ER

\-Primary function is lipid synthesis than released in vacuoles

\-Synthesis of lipids, steroids, carbohydrates

\-Metabolism of exogenous drugs/toxins/alcohol (breaks down toxins)

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Rough ER

primarily concerned with the synthesis, folding and modification of proteins

Golgi Apparatus

Composed of stocked, flattened sacs, where proteins and other molecules are processes and packaged for shipment.

\-Has Cisternae (which stick together using matrix proteins)

\-Organelle is supported by microtubules

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Actin filaments

Small diameter cytoskeletal fibers made of subunits of the protein actin.

\-More frequent in muscle cells

\-Help maintain the shape of the cell

Intermediate filaments

Cytoskeletal fibers whose size is intermediate between those of actin filaments and microtubules can be made from a variety of protein subunits.

\-Strengthen most in animal cells

Microtubules

Large diameter hollow cytoskeleton elements made of pairs of proteins a= q-tubulin and b tubulin

\-Chain altering between Alpha and Beta create a Protofilament

\-13 Protofilaments form the microtubule

\-Forms the spindle that helps chromosomes split

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Peripheral membrane

A protein found on the inner or outer surface of a cell membrane

Transmembrane

A protein that spans the lipid bilayer of a cell membrane

Diffusion

Spontaneous movement of atoms, ions, molecules of higher concentration to areas of lower concentration

Entropy

measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty.

Osmosis

Movement of water across a cell membrane, from an area of higher concentration.

Facilitated diffusion.

Diffusion of substances across cell membranes through integral membrane proteins.

Exocytosis

A process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane..

Endocytosis

Is the process of actively transporting molecules into the cell by engulfing it with its membrane

Peroxisome

Function is to break down toxic waste and lipids Because of this process they make their own chemical and toxic environment. Makes hydrogen peroxide.

ONCH

Oxygen is greater than nitrogen is greater than carbon is equal to hydrogen.

Hydrophilic

Water loving, polar charged, they come towards water

Hydrophobic

Does not dissolve in water, nonpolar bonds, they separate from water.

Plasma Membrane

A protein studded; fatty film so thin that it cannot be seen directly in the light microscope.

Phospholipid

Composed of two fatty acid tails linked to one of variety of phosphate containing polar groups.

Phosphatidylcholine

Common phospholipids present in abundance in most cell membranes, uses choline attached to a phosphate as its head group.

Saturated fatty acids

Include coconut oil, bacon grease, anything that is solid at room temperature.

Unsaturated fatty acids

Olive oil, vegetable oil, anything liquid at room temperature

Lipid bilayer

is **a thin polar membrane made of two layers of lipid molecules**

Phospholipids

a lipid containing a phosphate group in its molecule

Phosphatidylcholine

a class of phospholipids that incorporate choline as a headgroup.

Amphipathic

A molecule that has both polar and nonpolar parts

Easiest molecules to go through the lipid bilayer.

Small nonpolar molecules: O2, CO2, N2, Steroid hormones. Most will be able to go through

Hardest molecules to go through lipid bilayer.

Ions, H+, Na+, K+, Ca2+, Ci-, Mg2-, HCO3-. Will never go through.

Membrane potential

Voltage difference across a membrane due to a slight excess of positive ions on one side and of negative ions on the other.

Passive transport

The spontaneous movement of solute down its concentration gradient across a cell membrane via a membrane transport protein, such as a channel or a transporter.

Active Transport

The movement of a solute across a membrane against its electrochemical gradient; requires an input of energy, such as that provided by ATP hydrolysis..

Electrochemical gradient

Driving force that determines which way an ion will move across a membrane": consist of the combined influence of the ion’s concentration gradient and the membrane potential.

Aquaporin

Channel that facilitates the transport of water, but no ions, across cell membranes: those found in the plasma membrane greatly increase a cell’s permeability to water.

Turgor pressure

Force that builds as water flows into plant and yeast cells by osmosis drives the expansion of cells that underlies plant growth and maintians the rigidity of plant stem and leaves

Central Dogma

Flow of info from DNA to RNA

Bacteria

\-No nucleus

Biggest domain of 3

\-Most are single celled organisms

\-Tough protective coat

\-Aerobic or anerobic metabolism

Archaea

\-No nucleus

\-Predominant form of life in soil and seawater

\-Genomes of archaea are much closer related to eukaryotes than bacteria

Cytosol

\-Part of the cytoplasm that is not contained within intracellular membranes

\-Single largest compartment

\-Where chemical reactions occur

\-Where most proteins are made by ribosomes

\-Can go to the mitochondria, nucleus, peroxisomes, or chloroplasts via post and translational transport.

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Protozoans-Unicellular Eukaryotes

\-Sensory bristles

\-Photoreceptors

\-Sinuously beating cilia

DNA Contains the Genome

\-Genome contains the 23 chromosomes

\-Each chromosome contains a strand of DNA wrapped around proteins called Histones

\-Within strands of DNA are Genes which are responsible For making proteins

RNA attaches to the Gene

\-Enzyme called RNA polymerase attaches to the gene

\-Polymerase unwinds the DNA and makes a strand of messenger RNA using free bases in the nucleus

Kinesin

A motor protein that can change shape and move cargo

\-Needs ATP to be able to change shape and walk

Sodium Potassium Pump

\-Uses ATP to transport

\-Sends 3 Na3+ ions from inside cell to outside

\-Sends 2 K+ ions from outside cell to inside cell