Cell and Molec Exam 1 (Ch 1-3)

cells are the _____________________ unit of life

basic structural and functional

* the cell is the simplest collection of matter that can be alive
* every living thing can be broken down into cells
* all living organisms are composed of cells

Viruses are

not living things

without a host cell, viruses

* do not possess cellular structures
* do not metabolize
* are not motile
* do not reproduce

Cell morphology

shape structure of a cell

* important for determining function

Metabolic demands

* molecules being formed and broken down
* aerobic
* anaerobic

Aerobic

requires oxygen

Anaerobic

do not require oxygen

Prokaryotic cell structure

* only contain a membrane, cytoplasm, and DNA
* NO nucleus or membrane bound organelles
* formed before eukaryotes
* structurally simpler

Eukaryotic cell structure

* contains membrane bound organelles
* protists (unicellular eukaryotes), animals, plants, fungi
* compartmentalization!!

Domains within prokaryotes

Bacteria & Archaea

Domains within eukaryotes

Eukaryota

_____ organisms possess a cell wall

Most!

What has a cell wall?

* bacteria
* protists
* not all, but many can
* made of silica
* Fungi
* made of chitin
* Plants
* made of cellulose

Do animals have a cell wall?

NO

Cell wall functions

* shape and structural support
* protection against a hypotonic environment

\*\*does NOT control what goes in and out of a cell

Plasma Membrane/Cell Membrane functions

* selectively permeable
* controls entry and exit from the cell
* cell communication
* Adhesion
* separation of intracellular and extracellular environments

\*\*constantly moving → fluid mosaic

Adhesion

cells adhere to surfaces or other cells

All cells have ----, but not all cells have ------

* all have cell membranes
* not all have cell walls

The nucleus has a double phospholipid bilayer membrane called the

Nuclear Envelope

Nuclear pores

allows proteins to move in and out of the nucleus

* very restrictive

Nucleoplasm

cytoplasm in the nucleus

Nucleolus/Nucleoli

site of ribosomal RNA (rRNA) synthesis and assembly

Functions of the nuclear envelope

• contains and protects most eukaryotic DNA

• organization of DNA

Ribosomes

* composed of rRNA and protein
* non membrane bound organelle
* possessed by ALL cells

What is the function of ribosomes?

protein synthesis (translation)

Different populations of ribosomes in eukaryotic cells

* free (cytosolic)
* bound to the endoplasmic reticulum
* making a rough ER
* 1 or 2 additional populations

The outer nuclear membrane and the endoplasmic reticulum membrane are

connected to each other!

* is continuous

Rough ER

* site of synthesis for endomembrane system proteins and secreted proteins

Smooth ER

* synthesis of membrane lipids
* Ca 2+ storage (muscle cells)

Golgi Apparatus function

* processing, sorting, and shipping of molecules synthesized in the ER
* vesicle transport

Cisternae

* fluid filled membrane
* within golgi

vesicles fuse with the golgi on the ___ face

cis

vesicles leave the golgi on the ____ face

trans

Lysosomes

* acidified organelle specializing in digestion
* pH 4.5 - 5

functions of lysosomes

* degradation of material taken in my endocytosis
* breakdown of intracellular materials
* Autophagy

Endocytosis

bringing thing into the cell

phagocytosis

type of endocytosis where the cell engulfs/eats material

* cellular eating

autophagy

self eating

The Mitochondrion

* site of oxidative phosphorylation
* produces ATP
* ancestral eukaryote essentially engulfed a mitochondria (ancestral prokaryote)
* endosymbiosis
* site of cell respiration
* double phospholipid bilayer

oxidative phosphorylation

* electron transport
* chemiosmosis

matrix (in mitochondria bilayer membrane)

space inside inner membrane

* citric acid cycle occurs here

Cristae (in mitochondria bilayer membrane)

* inner mitochondrial membrane
* has lots of folds to increase surface area which results in higher production of ATP

Apoptosis

programed cell death

apoptosis could be caused by

* DNA damage
* metabolic stress
* oxidative stress

\*\*\*can not be stopped or revered

function of the Chloroplast

* site of photosynthesis (plants, photosynthetic protists)
* CO2 → Glucose
* using light energy

Components of a chloroplast

* Thylakoid
* Stroma

\*\*has double phospholipid bilayer membrane

Thylakoid

* where most of the proteins that help carry out photosynthesis stay

Stroma

fluid/aqueous solution in the organelle

Evidence of Endosymbiosis

* Mitochondria and Chloroplasts
* double phospholipid bilayer
* kept the cells membrane after engulfing
* have their own DNA (mtDNA, cpDNA)
* have their own ribosomes
* division mimics that of bacteria
* binary fission

The cytoskeleton

* the cells “muscles” and “bones”
* filamentous proteins → bone
* motor proteins → muscle

Cytoskeleton functions

* contributes to eukaryotic cell shape
* controls all aspects of eukaryotic cell motility

3 Types of Bonds talked about

• ionic bonds

• covalent bonds

• hydrogen bonds

Ionic Bonds

transfer of electrons to form a bond

• occurs between metals and nonmetals

Covalent Bonds

• sharing of electrons to create a bond

  • does not have to be equal sharing

  • occurs between 2 nonmetals

polar covalent bond

not equal sharing of electrons

• partial +/-

nonpolar covalent bond

equal sharing of electrons

Hydrogen Bonding

• molecules beside water participate in hydrogen bonding

• important for biological functions

• responsible for basic properties of H2O

what do you need for hydrogen bonding to occur?

• polar covalent molecule

• molecule with a hydrogen

hydrophilic

water loving

• ex: glucose

hydrophobic

water fearing

• ex: octane

Intermolecular bonding

bonding that occurs BETWEEN 2 molecules

Intramolecular bonding

bonding that occurs WITHIN a molecule

covalent bonds are the _________ and _____

strongest and shortest of the chemical bonds

noncovalent-ionic bonds are the _________

second strongest chemical bond

noncovalent-hydrogen bonds are the ______

third strongest chemical bond

Noncovalent Van Der Waals bonds are the ____

fourth strongest chemical bond

many inorganic ions function as enzyme

cofactors

• Mg2+

Inorganic ions

• Fe2+/3+

• Ca2+

• Mg2+

• K+

• Na+

• Cl-

• etc

organic molecules

• carbohydrates

• proteins

• nucleic acids

• lipids

only 3 organic molecules are polymers, which are they?

• carbohydrates

• proteins

• nucleic acids

which organic molecule is not a polymer

lipids

polymer

a molecule that is created by covalently attaching repeating subunits

• larger molecules made by building blocks

Levels of organization — Polymer

Monomer → Dimer (2) → Oligomer (few) → Polymer (many)

Polymerization

the process of joining subunits together by covalent bonds

• condensation (dehydration synthesis) reactions build polymers

Depolymerization

the process of breaking polymers into monomers

• hydrolysis reaction breaks bonds

Dehydration synthesis

water molecule is removed to join 2 molecules

Hydrolysis

water molecule is added to break 2 molecules apart

Level of organization — Sugars

Monosaccharides → Oligosaccharides → Polysaccharides

sugars are joined by

glycosidic linkages

sugars are a type of

carbohydrate

The role of monosaccharides

• energy generation

  • glucose

• synthesis of/conversion to other molecules

  • ribose/deoxyribose

The role of Oligosaccharides

• have special functions

  • Glycoproteins

  • Glycolipids

  • Glycosylation

  • Protein Structure

  • Cell-Cell Adhesion

  • Cell Identification

The role of Polysaccharides

• energy storage

  • starch (plant cells)

  • glycogen (animal cells)

• Cell Structure

  • cellulose (in cell wall of plants)

  • chitin (in cell wall of fungus)

What are the monomers of proteins?

• amino acids

levels of organization — Proteins

amino acids → (oligo)peptides → polypeptides → proteins

there are ____ different amino acids (R-groups)

20

Amino acids are joined together by

peptide bonds

3 parts of an amino acid

• amino group (NH3)

• R-group

• Carboxyl Group (CO2)

• central C-H

proteins have incredible structural and functional

diversity

protein functions

• DNA replication

• Structure & Motility

• Transport

• Communication

2 types of nucleic acids

• Deoxyribonucleic acid (DNA)

• Ribonucleic acid (RNA)

nucleotides are the monomers of

nucleic acids

what is the difference between DNA and RNA structurally?

DNA has a hydrogen attached to its 2’ end, whereas RNA has an OH attached to its 2’ end

Pyrimidines

• Cytosine

• Thymine

• Uracil

Purines

• Guanine

• Adenine

**2 car garage

Nitrogenous bases in DNA

• Adenine

• Thymine

• Cytosine

• Guanine

Nitrogenous bases in RNA

• Adenine

• Uracil

• Cytosine

• Guanine

Nucleotides are joined by

phosphodiester bonds

Nucleic acids have a ________ backbone

sugar-phosphate

polymerization (nucleic acids)

• bond between sugar and nucleotide and phosphate of the next