bio test 5-7

macromolecules

• large molecules that are made up smaller subunits: monomers and polymers

• ex: carbohydrates, lipids, proteins, nucleic acids

monomers vs polymers

monomers: small subunits that make up polymers (lipids)

polymers: larger molecules made up of a chain of monomers (carbohydrates, proteins, nucleic acids)

dehydration reaction

chemical reaction when 2 monomers are linked together and a water molecule is produced

• forms a water molecule when covalently bonded and leaves the monomers

• one monomer contributed OH-, other provides H+

hydrolysis

polymers are taken apart by the addition of a water molecule

• water molecule breaks covalent bond

• each monomer receives part of H2O (one OH-, other H+)

monosaccharides

monomers that build carbohydrates

• 3-7 carbons (mostly 5-6)

• all contain a hydroxyl group and at least one carbonyl group

carbohydrates

• large macromolecule that makes up organisms

• a sugar

• made up of monosaccharides

• Ones with 5-6 carbon sugars + carbonyl group + hydroxyl group can form a carbon ring

• ex: starch, glucose, cellulose

aldose vs ketose sugar

aldose sugar: a sugar with a carbonyl at the end of the caron chain

ketose sugar: a sugar with a carbonyl group in the middle of a carbon chain

disaccharides vs polysaccharides vs mono

monosaccharides= 1 sugar monomer

disaccharides= double sugars (2 mono’s joined by covalent bond)

polysaccharides= many sugars (many mono’s joined by covalent bonds) **used for energy storage

lipids

• not a true polymer (no repeating monomers)

• made of C, H, O

• ex: fats, phospholipids, steroid hormones

fat definition

• combination of glycerol and fatty acid chains

• hydrophobic

glycerol

• makes up fat

• alcohol which contains 3 carbons and 3 hydroxyl groups

fatty acid

• makes up fat

• hydrocarbon chain of 16-18 carbons—end carbon has a carboxyl group

triglyceride

important group of fats that are made up of one glycerol and 3 fatty acid chains

• body turns excess calories into triglycerides

• stored in fat cells and released into the blood stream when needed

• hydrophobic

saturated vs unsaturated fatty acids

saturated fats: have fatty acid chains that are saturated with hydrogens, maximal hydrogens covalently bonded (solids at room temp—stack, unhealthy)

unsaturated fats: have fatty acid chains that are not saturated with hydrogen, not at the maximal amount of hydrogen that could be bonded (liquids at room temp—bendy so they cannot stack to form solid, healthy)

cis vs trans fatty acids

double bonds in unsaturated fatty acids are either cis or trans

• H on the same side= cis (healthy)

• H on opposite sides= trans (unhealthy)

phospholipid

a lipid molecule made up of a glycerol, phosphate group and 2 fatty acid chains

• similar to triglyceride but the 3rd hydroxyl group of glycerol is attached to phosphate instead of a fatty acid

phospholipid bilayer

phospholipids organize into bilayers (tails associate together and heads associate with an aqueous environment)

• all cell membranes have a phospholipid bilayer inside as a protective barrier

steroid hormones

hormones with a carbon skeleton with 4 fused rings

• no glycerol subunit—grouped with lipids since they are hydrophobic

• derived from cholesterol

protein

one or more polypeptides folded into a specific 3D shape

• shape determines function

• function types: transport, chemical reactions, movement, etc.

• made up of amino acids

• consists of 1 or more polypeptides folded into a specific shape

amino acids

• building block monomers of proteins—backbone of protein

• contain amino and carboxyl functional groups around a central carbon

• all proteins are built from the same set of 20 amino acids

• have a side chain/R group for different things to attach to\linked together by dehydration reactions to form peptide bonds

polypeptides

the polymers that make up amino acids, and those amino acid monomers then make up proteins

peptide bond

covalent bond that holds amino acids together using dehydration reaction between carboxyl and amino groups of 2 amino acids

• this forms a polypeptide

4 levels of protein structure

primary: amino acids are joined together to create an amino acid chain

secondary: part of the amino acid chain (polypeptide) folds into alpha helices or beta sheets

tertiary: the whole polypeptide chain folds into a 3D shape

quaternary: multiple polypeptide chains come together to form one functional protein (not all proteins have this stage—only if multiple chains)

denaturation

the process of a protein losing its 3D structure

• bonds that hold proteins are weak, so they can denature

ex: changes in pH, temperature, salt concentration, can lead to denature (once the environment is restored it refolds)

nucleic acids

a polymer that stores information cells, can be used to make proteins

• made up of subunits nucleotides

• ex: DNA and RNA

nucleotides

monomer of nuclei acid made up of a nitrogenous base, pentose (5 carbon sugar) and 1-3 phosphate groups)

**sugar of DNA is deoxyribose, and ribose in RNA

cell theory 3 concepts

1. all organisms are composed of cells

2. cells are the basic unit of structure and function in an organism

3. all cells come from preexisting cells

cells ALL comprise of

• plasma membrane

• cytoplasm

• DNA

• ribosomes

plasma membrane/cell membrane

the membrane at the boundary of every cell

• made up of the phospholipid bilayer

• in all cells

cytoplasm

the contents of the cell within the plasma membrane (everything inside cell and outside nucleus)

• in all cells

ribosomes

small structures in cells that produce proteins

• in all cells

prokaryotes vs eukaryotes

prokaryotes: single cells organisms that do not have a nucleus or other membrane bound organelles (ex. bacteria)

eukaryotes: has a nucleus and other internal membrane bound organelles, larger than pro (ex. plants, animals, fungi)

nucleus

membrane bound control center of a eukaryotic cell

• where eukaryotic DNA is housed

• nuclear envelope: membrane that surrounds the nucleus—made of phospholipid bilater

• nuclear pore: small holes that allow transports in and out of the nucleus

nucleolus

condensed region in the center of the nucleus that produces ribosomes

• ribosomes are transported through the cytosol liquid in the cytoplasm to make proteins

ribosomes

• made up of RNA

• help to form protein

• free ribosomes: suspended in the cytoplasm

• bound ribosomes: attached to the ER or nuclear envelope

endomembrane system

collection of membranes inside a eukaryotic cell that work together to transport lipids and proteins

endoplasmic reticulum

• synthesizes and transports proteins and lipids

• accounts for over half of the membrane material in a cell

• 2 kinds: Rough ER and smooth ER

rough ER vs smooth ER

rough ER: has ribosomes attached to its surface

• proteins are made from ribosomes on the rough ER surface—ER then checks it and sends it out

smooth ER: no ribosomes on its surface

• helps with lipid synthesis, and detoxifies drugs/poisons

golgi apparatus

• receives the products of the Er for modification and is then sent to other destinations

• made of flat stacks of membranes called cisternae

vesicles

a membrane bound sac that is used to transport materials from organelle to organelle

lysosomes

membrane bound organelle that freely floats in the cytoplasm

• digest excess or worn out cell parts and recycle them into new parts

• only in animal cells

• help cells renew themselves

vacuoles

fluid storage sacs founded in plants fungi and animal cells

• there are small vacuoles in animal cells

• central vacuole: the single large vacuole in plants and fungi (absorbs water and provides strength)

mitochondria

• used in cellular respiration (uses oxygen + sugar to create ATP)

• converts sugars, fats, and other fuels into energy for cells

• NOT part of the endomembrane system

• semiautonomous: they grow and reproduce on their own within the cell

chloroplasts

• found in plants and algae

• used for photosynthesis

• converts solar energy into chemical energy

• NOT part of the endomembrane system

• semiautonomous: they grow and reproduce on their own within the cell

peroxisomes

an organelle that breaks down complex molecules and sequesters harmful substances

• detoxifies alcohol and harmful compounds

cytoskeleton

a network or protein fibers that extend throughout the cytoplasm of a cell

• provide support to the cell, helps with movement, helps with signaling and transportation

• made of microtubules, intermediate filaments, and microfilaments

microtubules

• largest part of cytoskeleton structure

• constructed from tubulin (a globular protein)

• organization is constantly changing throughout the cell cycle

• help with cell movement, transport, and chromosome movement

• ex: flagellum + cilia are kinds of microtubules

microfilament

• smallest size

• made up of linear chain of actin (binds to myosin protein for muscle cells)

• structural role in the cytoskeleton, helps to bear tension

intermediate filaments

• medium sized

• help cytoskeleton structure and bear tension—give physical strength to cells and tissues

• more stable than microtubules + microfilaments

• common in animal cells and not plants/fungi

cell wall

protective later external to the plasma membrane of many non animal cells

• plant cell walls: made of cellulose

• fungi cell walls: made of chitin

• bacteria cell wall: made of peptidoglycan

extracellular matrix

animal cells do not have a defined cell wall and have an extracellular matrix instead

• meshwork surrounding animal cells

how plant cells connect to each other (cell junction)

plasmodesmata: membrane lined channels filled with cytoplasm that connect adjacent plant cells

• allow for movement of water, ions, and molecules between plant cells

how animal cells connect to each other (cell junction)

1. tight junctions: plasma membrane of neighboring cells are tightly pressed against each other by specific proteins—prevent fluid from moving between cells

2. desmosomes: cells are fastened together into strong sheets, connected to intermediate filaments inside the cells, don’t pull apart when stretched

3. gap junctions: forms channels between neighboring cells, allows water + ions + molecules to move between cells

plasma membrane

• found in ALL cells regardless of type

• organized as a fluid mosaic model

• mediates transport of molecules in and out of the cell

fluid mosaic model

describes the cell membrane as a flexible, two-dimensional liquid where a mix of lipids, proteins, and carbohydrates constantly move and shift

phospholipids in the membrane

• main component of the plasma membrane

• amphipathic molecule: has a polar and nonpolar end (hydrophilic and hydrophobic)

• controls movement across the membrane

• helps to form the phospholipid bilayer

proteins in the plasma membrane

• proteins are interspersed throughout the membrane

• can be integral (span the whole membrane) or peripheral (found on one side of the membrane—the inside)

carbohydrates in the plasma membrane

short chains of carbs attach to the lipids and proteins on the outside of the membrane

• glycolipids: sugar chains attached to a lipid

• glycoproteins: sugar chains attached to a protein

membrane fluidity

the plasma membrane is fluid

• phospholipids can move and exchange places with each other, usually on the same side

• proteins can move

• fluidity decreases as the temp drops

• cholesterol prevents extreme changes in fluidity caused by temperature shifts

selective permeability

plasma membrane allows some substances to cross more easily than others

concentration gradient

the difference in concentration of a substance across a membrane

• a difference in concentration of a substance between two areas

• dont need to be connected—only for transport

passive transport + its types

• no ATP/energy is required

• substance moves down concentration gradient (high to low)

• diffusion is when small molecules move directly through the membrane

• osmosis is the diffusion of water across a selectively permeable membrane

• facilitated diffusion when a molecule moves from high to low but needs a membrane protein to help it cross

active transport

• requires energy/ATP

• substances move against concentration gradient (low to high)—does this to try and maintain a particular concentration in the cell

• bulk transport of big molecules

diffusion

• type of passive transportation

• molecules move so that they spread out evenly into the available space

• small molecules move directly through the membrane

• high to low concentration

osmosis

• type of passive transport

• movement of water across a selectively permeable membrane

• water balances itself on each side of the membrane

tonicity (hyper, hypo, iso)

• the concentration of a solution surrounding a cell

hypertonic= higher solute concentration than inside the cell (shrivels since water leaves)

hypotonic= lower solute concentration than inside the cell (swells since water goes in)

isotonic= equal concentration inside and outside the cell

tonic environments

hypotonic: cell swells against cell wall and cell wall prevents the water from escaping/cell to burst (turgid pressure—normal plant cell state)

isotonic: no net movement of water—cell is flaccid

hypertonic: water will leave the cell causing shriveling/plasmolysis

osmoregulation

regulation of solute concentrations and water balance by a cell or organism

facilitated diffusion

• type of passive transport—no energy

• passage of molecules down concentration gradient across a membrane with the assistance of transmembrane proteins (goes through channel protein and carrier protein helps it move across)

electrochemical gradient

diffusion gradient of an ion that is effected by the concentration gradient and membrane potential (difference in electrical charges across membrane due to ion differences)

exocytosis

• active transport

• moves molecules out of the cell

• waste removal, secretion, cell signaling

endocytosis

• active transport

• moves materials into the cell using vesicles

types:

• phagocytosis: engulfs large solid particles, cell eating

• pinocytosis: engulfs extracellular fluid and its dissolved solutes, cell drinking

• receptor mediated endocytosis: uses surface receptor proteins to capture target molecules