Bio Content Block 2

What are the 4 classes of Macromolecules and their function?

Carbohydrates - energy

Proteins - cellular functions

Nucleic Acids - transmission of hereditary info

Lipids - fats and steroids

What is dehydration reaction and what does it do?

Cells synthesize (build) polymers from monomers - also called condensation reaction

What is hydrolysis?

Cells break down polymers into monomers

Monosaccharide

1 sugar, monomer

Disaccharides

2 sugars, dimer

Polysaccharides

More than 2 sugars, polymer

Characteristics of monosaccharides

• monomers

• simple sugars

• typically 5-6 carbon atoms

• at least 1 carbonyl group (either aldehyde or ketone)

• 2 or more hydroxyl groups

• ring structure

• major nutrients for cells

Characteristics of disaccharides

• 2 monosaccharides joined by a covalent bond (called a glycosidic linkage)

Common disaccharides

Glucose + Fructose = Sucrose

Glucose + Galactose = Lactose

Glucose + Glucose = Maltose

Characteristics of polysaccharides

• many monosaccharides joined by glycosidic linkages - typically hundreds/thousands of monomers

• can be linear or branched

What are the 3 main types of carbs?

Starch, cellulose, glycogen

Characteristics of cellulose

• component of plant cell walls

• polymer of β-glucose monomers

• monomers are upside down compared to its neighbor

• forms parallel rows via hydrogen bonds

• indigestible by humans but aids in digestion (insoluble fiber)

Characteristics of starch

• potatoes, grains, roots

• polymers of α-glucose monomers (all in the same direction)

• can be digested by humans and many other animals

Characteristics of glycogen

• polymer of α-glucose monomers

• extensively branched

• digested by carnivores and omnivores

Characteristics of chitin

• made by animals

• structural support

• similar characteristics as cellulose

• can be somewhat digested by humans

• polymer of glucose with amino groups

What type of monomer is protein?

amino acid

Characteristics of proteins

• accounts for 50% of dry mass in most cells

• many types and functions

• each type has unique shape

• most diverse component of the cell

• all constructed from a set of 20 amino acids

What is the make up of an amino acid?

• alpha carbon in the center, attached to carbon is:

  • an amino group

  • a carboxyl group

  • a hydrogen atom

  • an R group

What are amino R groups?

• Can be functional groups, carbon chains, or carbon rings

• some are nonpolar and some polar

• each amino acid has a different R group

What are the protein structure levels?

Primary - peptide bonds

Secondary - hydrogen bonds

Tertiary - interactions b/w R groups

Quaternary - association of 2+ polypeptides

What does it mean for a protein to dentature?

Loss of 3D shapes (unravelling) due to extreme environmental conditions (pH, salt concentration, temp)

denatured proteins are nonfunctional

What is the monomer and funtion of nucleic acids?

nucleotide; functions in gene expression

What are the 2 types of nucleic acids?

DNA and RNA

What are nucleotides composed of?

• pentose sugar

• phosphate group

• nitrogenous base

What are nucleotides linked by?

phosphodiester bonds

What are the 5 nitrogenous bases?

Single Rings (pyrimidines)

• Cytosine

• Thymine

• Uracil

Double Rings (purines)

• Adenine

• Guanine

What are the base pairing rules?

DNA

• C-G

• A-T

RNA

• C-G

• A-U

What is the monomer of RNA and what is it composed of?

nucleotide;

• ribose sugar

• phosphate group

• nitrogenous base

BASES OF A,C,G,U

Characteristics of lipids

• organic molecules of carbon, hydrogen, and oxygen

• non polar hydrocarbons

• DO NOT mix with water

What polymer/monomer are lipids?

They are not true polymers - there is no one monomer subunit in common

What are the types of lipids?

• fats

• phospholipids

• steroids

What are the components of fat molecules?

1 glycerol attached to 3 fatty acids (called a triglyceride)

What is a glycerol?

an alcohol, 3 carbon chain, each chain has a hydroxyl group

What is a fatty acid?

long hydrocarbon with carboxyl group at the end

(hydrophobic because of the long hydrocarbon chain)

What are the different types of fatty acids?

• saturated fat “bad”

• unsaturated fat “healthy”

• trans fats “partially hydrogenated oils, pHOs

Characteristics of phospholipids

• biologically crucial

• cells couldn’t exist without them

• Amphipathic

Structure of phospholipids

• 1 glycerol

• 2 fatty acid tails

• phosphate group

• 1 other small positively charged molecule (varies in different phospholipids)

Amphipathic

hydrophilic and hydrophobic portions

Characteristics of steroids

• lipids with skeleton of 4 fused carbon rings

• hydrophobic

• different types of steroids have different functional groups

• cholesterol is a steroid

Cholesterol chcaracteristics

• allows fluidity of cell membrane (very important in cold environments)

• precursor to hormones

Example of carbohydrate

starch, glycogen, cellulose

Example of proteins

enzymes, antibodies

Examples of nucleic acids

DNA and RNA

Examples of lipids

fats - saturated, unsaturated, trans, cholestserol

Difference between prokaryotes and eukaryotes

Prokaryotes

• single cells organisms

• from archae and bacteria domains

Eukaryotes

• single celled or multi celled organisms

• from eukarya domain

• includes protists, fungi, plants and animals

• membrane bound organelles

• larger

Similarities between prokaryotes and eukaryotes

• plasma membrane

• DNA

• ribosomes

• cytosol

Difference between eukaryotic plant and animal cells

Plant

• cell wall outside of the plasma membrane

• chloroplasts

• central vacuole

• square

Animal

• lysosomes

• centrosomes

• round

Plasma membrane

• phospholipid bilayer with embedded proteins and cholesterol

• separates cell from external environment

• regulates what comes in and out of cell

Cytosol

the fluid within cytoplasm - surrounds organelles/site of many chemical reactions

Cytoplasm

all content within the cell membrane

Nucleus

• site of DNA replication and mRNA synthesis

• contains chromosomes

• contains nucleolus - for production of ribosomes

• has pores for molecules to go in and out

Ribosomes

• site of protein synthesis

• made of rRNA and proteins

• no membrane

2 types of ribosomes and functions

Free

• floating, produce proteins that are mostly used in the cell

Bound

• bound to the ER, produce proteins mostly exported out of cell

Endomembrane system

• group of organelles involved in protein and lipid synthesis and modification

  • nuclear envelope

  • endoplasmic reticulum

  • golgi apparatus

  • lysosomes

  • vesicles

• resulting proteins/lipids are '“shipped” to various locations (UPS system of cell)

Endoplasmic reticulum

• network of flattened tubules

endo- “in the” cytoplasm

reticulum- “little net”

• plays key role in protein and lipid synthesis

Rough ER

• proteins produced here are transported to the golgi apparatus

• bound ribosomes

Smooth ER

• no ribosomes

• produces various lipids - fatty acids and steroids

• detoxifies - drugs, poison, alcohol, etc

• Storage for calcium ions (which are used in cell signaling)

• lipids produced here are transported to golgi apparatus in vesicles

Golgi Apparatus

• “FedEx” of the cell

• made of flattened stacks

• Materials are transported b/w the stacks via vesicles

  • cis face = closest to ER

  • trans face = closest to plasma membrane

What are the 3 primary functions of golgi apparatus?

• processing - further modification of proteins and lipids that came from SER and RER

• protein and lipid sorting - determines which proteins/lipids stay in cell and which are exported out

• secretion - packages lipids/proteins into secretory vesicles that fuse with plasma membrane and are released outside of cell

Mitochondria

• produces ATP

• site of cellular respiration

• 2 phospholipid membranes - outer and inner

• resembles bacteria - own DNA and RNA

Lysosomes

• ANIMAL CELLS ONLY

• digestive vesicles

• assists with phagocytosis

• assists with autophagy

Phagocytosis

digests pathogens/foreign particles/food

Autophagy

breakdown/recycle damaged organelles

What is Tay-Sachs a result of?

damaged lysosomes

Peroxisomes

• function in detoxification

• removes hydrogens from toxic compounds and transfer them to O2

• hydrogen peroxide into water

• abundant in liver and kidneys

• helps breakdown very long chain fatty acids (VLCFA)

Cytoskeleton

• network of fibers used for structural support, organization, anchoring, movement

• eukaryotes, not prokaryotes

What are the 3 types of cytoskeletons in eukaryotes?

• microtubules

• intermediate filaments

• microfilaments

Microtubules

• largest

• hollow tube

• made of tubulin

• functions in shape, cell division, and motility

Intermediate filaments

• coiled keratin protein strands

• cell anchoring

• not found in plant cells

Microfilament

• thinnest

• 2 strands of actin (protein)

• functions in muscle contractions and cellular movement

Chloroplasts

• PLANT CELLS ONLY

• site of photosynthesis (sunlight → energy → G3P (precursor to glucose)

• 2 phospholipid membranes - outer and inner

• resembles bacteria (own DNA and ribosomes)

Endosymbiosis Theory

Ancient eukaryotic cell engulfed mitochondria and/or chloroplast.

Over time, this became a symbiotic relationship; host cell; host cell and engulfed cell became 1 organism

Cell junction animal cells

• tight junctions - plasma membranes of cells held tightly together, forms continuous seal

• desmosomes - anchors cells together

• gap junctions - cytoplasmic channels between cells

Cell junctions plant cell

• plasmodesmata- cytoplasmic channels b/w cells

What type of reaction is this?

Condensation (Dehydration) Synthesis

What kind of reaction is this?

Hydrolysis

What is this?

Glycerol

What is this?

Fatty acid

Saturated fatty acid

Unsaturated fatty acid

Trans fatty acid

prokaryotic cell

eukaryotic cell