Biology Unit 1 Grade 12 Test

Macromolecules

• large chain molecules

• carbs, proteins, lipids & nucleic acids

• referred to as —> polymers

• connected with covalent bonds

polymers

large molecules made by repeating subunits (monomers)

carbohydrates

• short term energy, large term energy, structure molecules

• made of CHO (1:2:1)

• lots of hydroxyl endings (-OH)

• makes molecules polar —> water soluble

monosaccharides

• 1 sugar

• Glucose, fructose, galactose

Disaccharides

• 2 sugars

• surcrose

Polysaccharides

• 72 sugars combined

• starch, glycogen, cellulose

Lipids

• made of CHO

• non polar

• few hydroxyl endings

• smaller complex molecules

Function

• long term energy storage

• protects organs

• insulation

• hormones (communication molecules)

• dissolving fat-soluble vitamins

• Phospholipids —> cell membrane

• nervous system —> myelination of nerves (protect from signal loss)

• ear wax (prevents fungi/bacteria in ears)

Fatty Acids

Hydrocarbon chains with carboxyl ending

Saturated fat

single bond between carbons

• max num of H

• straight linear molecule

• stackable + will do LDF

• solid at room temperature

• animal fats —> butter +lard

Unsaturated fats

• carbon atoms have double bonds between

• less hydrogen per molecule

• no stacking

• liquid at room temperature (oil)

• plant fats

Steroids

molecules with 4 carbon rings attached to a functional group

(testosterone, estrogen, cholesterol, communication, growth)

*note: cholesterol: maintains cell fluidity*

waxes

• large hydrophobic molecules

• non polar

• water proving

• ex:

  • ear wax

Proteins

• most diverse of macromolecules

• 25,000 in human body

• Polymer made out of amino acid monomers

• Amino acids —> CHONS

• Make up enzymes (biological catalysts)

• 20 amino acid monomers —> sequence is determined by DNA (codon)

• Structure, Movement (of substances), Hormones, Immune System (SHIMoS)

Sequence of Protein

1) (image)

2) (image)

3) sheet + helix structure (tertiary)

4) Polypeptide chain

*3 and 4 are functional groups*

Denature

• 2°, 3°, 4° don’t work anymore

• pH and temp sensitive

Digest

• breaking into 1°st structure

Nucleic Acids

• DNA —> deoxyribonucleic acid —> deoxy ribose phosphate base (A T G C)

• RNA —> ribonucleic acid (ribose sugar + phosphate) (A U G C)

DNA

• provides code for amino acid sequence

• information molecule

• stable molecule

• double stranded

• forms helix with H bonds in middle

RNA

• does a lot in cells

• single stranded (can form small double)

• small(er) molecule

• variable structure bc OH and 2nd C

• examples:

  • mRNA

  • rRNA

  • siRNA

  • TRNA

  • snRNA

Intramolecular forces

• found within molecule: ionic/covalent bonds

• Intramolecular forces can affect intermolecular forces

• electronegativity of atoms

  • results in polar molecules(dipole)

    • polar molecules - molecule w unbalanced electric charges

• Polarity of biological molecules greatly affect behavior and function in cell

Origin of Life

• need certain elements and molecules (CHONPS) + universal solvent (water)

• abiogenesis = life from not life

• hydrothermal cells were prokaryotic (3.5-3.8 bya) (lived in hydrothermal)

• last universal common ancestor —> single celled organism

• lived between 3-4 bya

• likely used RNA to store info + had phospholipids in membrane

• rRNA and ribosomes present

• Two prokaryotic domains

  • Eubacteria

  • Archaea

Endosymbiosis

• Two prokaryotic cells bond together to make a eukaryotic cell

• archaea engulfed an ancestor of purple bacteria

  • purple bacteria —> good at generating ATP (origin of mitochondria)

• Binary fission reproduction

• Mitochondrial ribosomes are essentially bacterial ribosomes

• Happened again —> origin of chloroplasts 1.5bya

• some evidence to support chloroplast

• other organelles —> membrane based formed by in-folding of phospholipid membranes

• origin of nuclear membrane and endoplasmic reticulum and golgi body

• other vesicles are part of this continued process

cell membrane

• regulates what enters and exits body

• only selective materials enter

• control movement of substances near, or inside the cell

cytoplasm

• holds molecules for cellular process

• protects it from any damage

nucleus

• contains genetic information

• responsible for cell division

• responsible for ribosomes

nucleolus

• denser than nucleus

• stores RNA

• protein chromatin

• responsible for ribosomes

nuclear envelope

• double membrane consisting of double phospholipid bilayer

• separating nucleus from rest of the cell

Smooth Endoplasmic reticulum

• synthesizes lipids and lipid-containing molecules (ie: Phospholipids)

• performs other functions depending on location

Rough Endoplasmic reticulum

• located w ribosomes

• synthesizes protein

• transports protein

• folds proteins

vesicles

transport materials within cell

such as

• water

• hormones

• communication

Golgi Apparatus

• processes and sends proteins/lipids within cell

• sorts them based on location

• packages into vesicles for transport

Lysosomes

• breaking down and recycling cellular waste or foreign invaders

• maintains cellular health

Chloroplasts

• organelle in plant cells

• captures light energy from sun

• stored as high - energy molecules (ie: glucose)

Mitochondria

• eukaryotic cells

• break down stored energy

• converts into visible energy

Cell Wall

• composed of proteins or carbohydrates

• gives cell its shape

• structural support and protection

Cytoskeleton

• extends through cytoplasm

• provides structure

• anchors cell membrane/organelles in place

Cillia

• move fluids, mucus, small particles across surface of cell

• moves the whole cell in unicellular organisms

Flagella

propels cell through liquids

Peroxisomes

• contains enzymes that transfer hydrogen from substances to oxygen —> H2O as byproduct

• formed in Endoplasmic reticulum

• various functions:

  • break fatty acids down into smaller molecules for cellular respiration

  • detoxify alcohol in liver

Lysosomes

• used by cell to digest macromolecules

• sac of hydrolytic enzymes

• apoptosis

• (usually) found only in animal cells

• formed in golgi body

what are phospholipids composed of?

two fatty acids

glycerol unit

phosphate group

Phosphate heads are attracted to (1)_______ and hydrocarbon tails are attracted to (2)_______ but not ______(same as (1))

(1) water

(2) each other

Due to this, the phospholipids are arranged in (1)_______ with the hydrophilic heads pointing out on either side and the hydrophobic tails facing (2)_______

(1) bilayer

(2) inward

Describe fluid mosaic model

Visualizes the cell membrane as a mosaic of proteins and other molecules in a fluid phospholipid bilayer.

consists of: phospholipids, proteins, cholesterol, carbohydrates

these components give membrane fluid character

Hydroxyl (include properties, structural formula, an example, and what it’s found in)

• Polar

• Ex: Ethanol

• Found in

  • carbohydrates

  • proteins

  • nucleic acids

  • lipids

Carbonyl

• Polar

• Ex: acetaldehyde

• Found in:

  • carbohydrates

  • nucleic acids

Carboxyl

• Polar (acidic )

• Ex: Acetic Acid

• Found in:

  • Proteins

  • Lipids

Amino

• Polar (basic )

• Ex: Alanine

• Found in:

  • Proteins

  • Nucleic Acids

Sulfhydryl

• Slightly Polar

• Ex: cysteine

• Found in:

  • Proteins

Phosphate

• Polar (negatively charged )

• Ex: glycerol phosphate

• Found in:

  • Nucleic Acids

Endomembrane system

• internal membranes formed by in-folding of phospholipid membrane

• origin of nuclear membrane and later ER and golgi body

• series of membrane based organelles that create, modify, process and deliver cell products within/outside cell

• RER and SER, goldgi and transport vesicles (peroxisomes, lysosomes, secretory vesicles)

• continuous process-membranes bud and merge; dynamic/fluid system

Endoplasmic Reticulum

• made uup of membranous tubules and cisternae (sacs)

• smooth ER; no ribosomes

  • synthesis and transport of lipids

  • controls glucose ←→ glycogen conversion in liver muscles

  • detoxification of drugs/poisons

• rough ER: ribosomes attached

  • synthesis and transport of proteins

Golgi apparatus

• products of ER are modified and storied here

• modifies and packages proteins

Endocytosis

• cell membrane engulfs material by folding inward which pinches off to create vesicle within the cell

Phagocytosis

cell engulfs solid particles

Pinocytosis

cell engulfs liquid particles

Receptor Mediated Endocytosis

receptor proteins on the cell membrane bind to specific molecules

Exocytosis

Secretory vesicle fuses with the cell membrane and releases contents to exterior of cell

Osmosis and solute

• solutes in solution determine osmotic concentration

• if two solutions have unequal osmotic concentrations —> solution w higher concentration is hypertonic and solution with lower is hypotonic

• if they have osmotic concentration —> isotonic

• water flows from hyper to hypo

• *cells in solution: hypotonic*

Hemolysis and what is the process in plant cells?

when too much water is in the cell (animal cells)

• in plant cells they prevent lysis and becomes turgid

• cells in solution: hypertonic

crenation

• crinkling/shriking of cell

• (in plants: plasmolysis wilting)

Factors Affecting Rate of Movement

• concentration : steepness of gradient

• polarity of molecule

• shape/size of particle

• temperature

• pressure

• presence/absence of facilitated particles

Active Transport across cell membrane

• against concentration gradient

• requires energy in the form of ATP

• adenosine + triphosphate(ATP_ →(H2O) = Adenosine + diphosphate+phosphate + energy (ADP)

Primary Active Transport

Move molecules or ions across membranes against a concentration gradient

ex: sodium-potassium pump

Secondary Active Transport

• uses concentration gradient of an ion established by primary pump as energy source

• creates an electrochemical gradient which creates electrical potential energy

Membrane Assisted Transport

larger molecules must move into or out of the cell through membrane assisted transport

requires endo and exocytosis

Fluid Mosaic Model of Phospholipid Bilayer

• semi fluid phospholipid bilayer w variety of proteins and carbohydrates attached to lipids or proteins

• fluid nature —> heads out, tails in (viscosity like vegetable oil)

• factors affecting fluidity: temp, how bendy, fatty acid length)

  • longer length=less fluid

• Presence of cholesterol

  • high temps: decreases fluidity

  • low temps: breaking up and increases fluidity

• Bilayers are made up of phospholipids; act as scaffolding (where proteins/macromolecules embedded)

• glycoproteins and glycolipids —> proteins and lipids covalently bonded to carbohydrates

• proteins in layers —> integral and peripheral

Integral proteins

embedded

Peripheral

Attached to one side

Passive transportation

• movement of materials across cell membrane w/o expenditure of energy

  • simple diffusion

  • osmosis

  • facilitated diffusion

    • facilitator protein required 1) channel proteins 2)currier proteins

Diffusion

movement of molecules from area of high to low concentration

Osmosis

diffusion of water across semi-permeable membrane

Facilitated Diffusion

movement of molecules from high to lower w/ assistance of membrane protein

• membrane protein have hydrophilic interiors that allow passage of polar/charged molecules