CAS BI 114 Lecture Notes - Lecture 1: Lipid Bilayer, Biomolecule, Monomer

83 views10 pages

raspberryserval680

30 Apr 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Biomolecules

Water and Cells

•All cells are in watery internal environments and most need to remain in these watery external

environments for survival

•How molecules interact with water is important biologically

Large Molecules

•Monomer - a single unit of a molecule is called a monomer (one building block)

•Polymer - a bunch of monomers together (several connected building blocks)

•Monomers-Polymers-Monomers

•Often you need an enzyme to achieve these

•Dehydration Reactions - reactions used to build a polymer from monomers

•Hydrolysis Reactions - reactions used to break down down a polymer into monomers

Biomolecules

•Organic molecules associated with living organisms

•Each of these molecules is an organic compound (it contains carbon and hydrogen)

•4 major groups

•Carbohydrates

•Most abundant biomolecule

•Polar (therefore, water soluble)

•monomer = monosaccharide

•ex: Glucose, Fructose

•polymer = polysaccharide

•ex: Sucrose (glucose + fructose), Lactose (glucose + galactose), glycogen (stored in the human

liver), starch, cellulose “fiber”, chitin

•Complex polysaccharides are called starches

•Most carbohydrates end in -ose

•Lipids

•Non-polar (not soluble in H20)

•Significant source of energy storage (lots of Carbon bonds)

•monomer = fatty acid

•polymer (3 fatty acids) = triglycerides

•Aqueous Environment

•Lipids bond together with hydrogen bonds

•Form a phospholipid bilayer on top of the heads

•Each lipid points its tail inwards to form a protective circle with the combined unit of heads

•Proteins

•Most versatile of biomolecules

•Polar (therefore, water soluble)

•monomer = amino acid

•polymer = polypeptide

•Building polypeptides

•Amino Acids join together through dehydration reactions that form peptide bonds

•Transport Proteins - proteins can operate as hydrophilic channels across the membrane to bridge

two watery environments on either side

•Protein Examples:

•Antibodies - proteins that prevent us from getting sick

•Enzymes - proteins that catalyze (speed up) reactions

•ex: lactase is an enzyme that breaks down lactose

•One way to characterize bacteria is by which enzymes they express

•We can determine this by what molecules each bacteria is able to break down

•Substrate: the molecule that the enzyme acts on

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in

•*All ligands are substrates, not all substrates are ligands

•Nucleic Acids

•monomer = nucleotides

•polymers = nucleic Acids

•Nucleic Acids: two varieties - DNA & RNA

•Composition

•A phosphate groups

•A 5 carbon sugar

•A 3 carbon nitrogen ring structure called a nitrogenous base

•Bases:

•Adenine - Thymine

•DNA - double stranded molecule

•RNA - single stranded molecule

•***ATP is a nucleotide that transfers energy within a cell

Transcription & Translation

•The central dogma of biology

•DNA —transcription—> RNA —translation—> Protein

•Transcription - take the DNA and make an RNA copy of it

•Translation - take the RNA and use it to make a protein

•Specific Steps:

•1. Synthesis of mRNA

•2. Movement of mRNA from nucleus to cytoplasm

•3. Attachment of mRNA onto a ribosome

•4. Synthesis of protein

Diffusion & Osmosis

•Diffusion - molecules of the same type will move away from each other

•Osmosis - diffusion with water molecules

•Solute v. Solvent

•Solute - what is dissolved

•Solutes SUCK - solute will suck solvent in their direction

•Question: If we move the solute, does the area gaining the solute gain volume? No.

•Solvent - what is the dissolver

•Tonicity

•The number of particles in any solution surrounding a cell

•Describes changes in cell volume if a cell is placed in a solution

•More water molecules on the outside

•Tonicity - the ability of the surrounding solution to cause a cell to gain or lose water

•Hypotonic (less particles on the outside, more water on the outside) - water will move in and the

cell will burst

•Hypertonic (more particles on the outside, less water on the outside) - water will move out and

the cell will shrivel

•Isotonic (same amount of particles on the outside) - will be normal

•Osmosis & Bacteria

•Most microbes are resistant/intolerant to high solute concentration

•ex: some are very tolerant of salt

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in

Cells

•Made by biomolecules

•Function as independent life units

•1 bacteria = 1 cell = 1 organism = 1 human = 75 trillion cells

•Each cell contains an entire organism’s genome

•Every cell is bound by a phospholipid bilayer

•Most cells have Glycocalyx - a coat of polysaccharides and proteins

•Some cells have a Cell Wall (ex: plants, unicellular organisms) based on their chemical compositions

Cell Movement

•Cilia - short, brush-like tails used for cell movement or movement of a substance across the surface of

the cell

•Flagella - long, often singular tails used for cell movement through extracellular fluid

Eukaryotic vs. Prokaryotic

•Eu = true

•Eukaryotic cells have a true nucleus

•All DNA is housed within the nucleus

•Pro = no

•Prokaryotic cells have no nucleus

•All DNA is gathered in a clump in the center of the cell

•Differences

•1. Cell Walls - eukaryotic animal cells lack cell wall

•This allows antibiotics (ex: penicillin) to attack human cell walls

•2. Ribosomes - bacterial and eukaryotic ribosomes are slightly different but both have ribosomes

•3. Size - eukaryotic cells are about 10x bigger

•4. Organelles - eukaryotic cells have many organelles with a variety of functions

Prokaryotic Cells (ex: bacteria)

•Unicellular organisms

•These cells are smaller than eukaryotes

•These cells have no membrane-bound organelles

•These cells gather DNA in the center of the cell

•These cells make up 10% of the average eukaryote body

Eukaryotic Cells (ex: animal, plant, fungi)

•These cells have many specialized organelles within the cytoplasm

•These cells have many vesicles (membrane sacs) that move materials from place to place (ex: the

movement of proteins)

•These cells range in size, specialization and appearance

•These cells are less protected against outside changes, temperature changes, etc. than bacterial cells

Membrane Proteins

•Membranes allow two different cells to interact with each other

• The exterior coat of the virus/cell (what is trying to attack the cell) needs to recognize the on-site coat

of the receptor (what is on the surface on the cell)

Cytoplasm - the watery interior of the plasma membrane

Cytoskeleton - a network of fibers running through the cell

•Can help with the transport of organelles around cells as well as the organization of the cell’s internal

components

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in

Related Questions

Question 401 pts

Kinetic energy is the stored energy that can be used for motion.

True

False

Flag this Question

Question 411 pts

When an electron is transferred from one atom to another, and the two atoms are then electrically attracted to one another, a(n) ________________ bond is formed.

Flag this Question

Question 421 pts

Changing the number of ____________ of an atom would change the chemical properties of the atom.

Flag this Question

Question 431 pts

Forming molecules and breaking down molecules in biological organisms usually requires the use of _________ to help the reaction proceed faster.

Flag this Question

Question 441 pts

Organic molecules have a core composed of .

Flag this Question

Question 451 pts

The building blocks of carbohydrates are

Flag this Question

Question 461 pts

Water molecules crossing a membrane from high to low concentration is .

active transport

cell fate

facilitated diffusion

osmosis

Flag this Question

Question 471 pts

Choose the membrane molecule responsible for the passage of polar molecules and ions into and out of the cell.

phospholipids

transmembrane channel proteins

cell surface proteins

carbohydrate chains

Flag this Question

Question 481 pts

The simplest cells are .

Flag this Question

Question 491 pts

Which of the following membrane bound organelles are found inside bacterial cells:

nucleus

organelles are not found in prokaryotic cells

mitochondria

chloroplasts

Flag this Question

Question 501 pts

Which of the following is a specialized components of the cell, is associated with the rough endoplasmic reticulum, and is responsible for making proteins.

Flag this Question

Question 511 pts

Proteins are sorted, modified, and packaged by the _____________ and later transported to the outside of the cell.

ribosomes

golgi bodies (golgi apparatus)

nucleus

mitochondria

Flag this Question

Question 521 pts

Dehydration synthesis is a process of linking two smaller subunits together to form a polymer. Which of the following statements below is true of dehydration synthesis?

Oxygen is consumed.

A water molecule is removed from the molecules.

A water molecule is added to the molecules

Carbon dioxide is given off.

Flag this Question

Question 531 pts

Proteins are made up of _________ held together by peptide bonds.

Flag this Question

Question 541 pts

Which of the following gives an amino acid its properties?

NH2

R Group or functional group

COOH

Flag this Question

Question 551 pts

The final three-dimensional shape of a protein that includes the bonding of two or more polypeptide chains is call its _____ structure.

Flag this Question

Question 561 pts

How do DNA and RNA differ?

all statements are differences between DNA and RNA.

DNA is double stranded while RNA is single stranded.

They have different sugars.

Thymine is present in DNA but not in RNA.

Flag this Question

Question 571 pts

Which of the following is a component of a DNA nucleotide?

phosphate

a nitrogen containing base

All are components of a nucleotide.

5-carbon sugar

Flag this Question

Question 581 pts

Cell membranes are made up of several different types of molecules. Select the membrane molecule below that is made up of a polar region and two non-polar fatty acid tails.

transmembrane proteins

carbohydrate chains

phospholipids

cell surface proteins

Flag this Question

Question 591 pts

Two organelles which are believed to have once been free-living bacterial cells are ____________ and ______________.

chloroplasts and mitochondria

golgi apparatus and endoplasmic reticulum

ribosomes and nucleolus

peroxisomes and lysosomes

Flag this Question