Exam 2 Flashcards
What are the 4 macromolecules that are common to all life?
Carbohydrates, lipids, proteins, nucleic acid
Organic chemistry
branch of chemistry that deals with organic molecules
Organic molecule
molecules that always contain a carbon and a hydrogen
Example of organic molecule
glucose( C6H12O6)
How many electrons does carbon only have?
6
Functional group
Is a specific combination of bonded atoms that always react in the same way
Dehydration reactions
Take place when the cell removes a water molecule* and two smaller molecules are joined
Hydrolysis reactions
Occur when an -OH group from water attaches to one subunit, and an -H from water attaches to the other subunit
Hydro - water Lysis - breaking
Enzymes
are molecules(proteins) that speed up reactions by bringing reactants(anything that goes into a reaction) together.
*Enzymes are required for both dehydration and hydrolysis reactions
Polymers
large biomolecules that are formed by linking “subunits” together
poly= many mer= parts
Monomers
The name given to the “subunits” that come together to build polymers
Carbohydrates
Used as an immediate energy source in living things
*Also can play structural roles (Cellulose, Chitin, Peptidoglycan)
cellulose
carb used in the cell wall of plants
Chitin
found in the shell of crabs and the exoskeleton of other inverts
Peptidoglycan
Found in the cell wall of bacteria
Carbohydrates contain carbon, hydrogen and oxygen in what ratio?What is an example of a carbohydrate?
1:2:1 ratio
Ex- glucose: : C6H12O6
Monosaccharides: Ready Energy
consist of only a single sugar molecule. They are called simple sugars.
*Contain from 3 to 7 carbons.
Examples of monosaccarides
Glucose (C6H12O6) is the most common
▫Has many isomers: molecules with identical molecular formulas, but different arrangement of atoms
Fructose
Galactose
•Ribose and Deoxyribose are 5 carbon sugars that used in RNA and DNA
Glucose is called a
“Hexose” – 6 carbons
Ribose and Deoxyribose is called a
Pentose – 5 carbons
Disaccharides: Varied Uses
contain two monosaccharides joined by a dehydration reaction
*Digestive juices later break this down back into glucose
Examples of disaccarides
Sucrose, Lactose(milk sugar)
Polysaccharides: Energy Storage Molecules
- Polymers of monosaccharides
- Often used as long term energy storage molecules.
*When the cell requires energy, the polymer is broken down to release sugar molecules
Examples of polysaccharides
- Starch – form in which plants store glucose
- Glycogen – form in which animals store glucose
**In liver, glycogen is stored in granules. The hormone (insulin) promotes the storage of glucose in the form of glycogen
What are the structural molecules of polysaccarides?
▫Cellulose
Cell wall of plants
Most organisms lack the enzymes needed to break down cellulose for energy
*Cellulose – Full of energy (ex. When you burn firewood, energy from heat and light comes from cellulose being broken down)
-We don’t have the enzyme to break it down
What eats wood? (termite) **They don’t have the enzyme either!
-In the gut of termites, there are protist that do have the enzymes to break it down. Without the protist, the termites wouldn’t be able to get energy from wood.
▫Chitin
Structural material found in fungi & the exoskeletons of insects and other invertebrates
▫Peptidoglycan
Structural polysaccharide in bacteria
Lipids
are a group of organic compounds that are not soluble in water.
Example of lipids
▫Fats
▫Oils
▫Phospholipids
▫Steroids
▫Waxes
Phospholipids
are constructed like triglycerides, except the third fatty acid is replaced with a phosphate.
Waxes
are formed when long fatty acid chains bond with long-chain alcohols
Amino acids
building blocks of proteins
Peptide
is two or more amino acids bonded together.
Polypeptide
is a chain of many amino acids joined by peptide bonds
Primary structure
•amino acid sequence of the polypeptide chain
*Chain could be from 100 to 5000 amino acids
Secondary structure
forms when the polypeptide chain folds back and forth on itself(pleated) or coils like a spring due to hydrogen bonds
Tertiary structure
forms when secondary structures bond, forming large folds that form unique 3-dimensional structures
Quaternary structure
forms when multiple polypeptide chains connect to form a single protein molecule
Denaturation
occurs when proteins lose their tertiary or secondary structure
Temporary vs Permanent Denaturation
Temporary(perm)
Permanent(fried egg)
Chaperone proteins(recently discovered)
help new proteins fold into their shape.
nucleotides
The building blocks of nucleic acids
Examples of nucleotides
▫DNA (Deoxyribonucleic Acid) – genetic material that stores information regarding the order of amino acids
▫RNA (Ribonucleic Acid) – Conveys information from DNA regarding the amino acid sequence in proteins
▫ATP (Adenosine Triphosphate) – nucleotide that supplies energy for reactions in the cell
Adenosine Triphosphate (ATP)
Is a molecule that carries energy in a form that the cell can use.
•Each ATP molecule consist of:
▫An Adenine
▫A Ribose
▫3 phosphates in a chain
Adenosine Diphosphate (ADP)
•When an ATP molecule looses a phosphate, it becomes Adenosine Diphosphate (ADP).
Phosphorylation
ATP can be made from an ADP molecule by reattaching a phosphate using energy released from cellular respiration.
Liquid at room temp
Unsaturated fats
Solid at room temp.
Saturated fats
Magnification
the ratio between the size of an image and its actual size
Resolution
the ability to see two objects as separate
Contrast
difference in the shading of an object compared to its background
Field of view
The amount of the specimen you can see
Depth of Focus
the thickness, or vertical distance of a specimen that can be seen all in sharp focus at one time
Working distance
The distance between the objective lens and the slide
Matthais Schleiden
1838 – German botanist Matthais Schleiden stated that all plants are composed of cells
Theodor Schwann
1839 – German zoologist Theodor Schwann declared all animals are composed of cells
Rudolph Virchow
**1850’s German physician Rudolph Virchow view the body as a state in which cells were citizens. Stated – “every cell comes from a preexisting cell”
Cell Theory was based on the work of
Schleinden, Schwann, and Virchow
Cell Theory
- All organisms are composed of cells
- Cells are the basic units of structure and function in the organism
- Cells com only from preexisting cells are self-reproducing
Cell Size
Cells vary in size, but are generally smaller that the eye can see.
Cells are small, because they need a large surface-area-to-volume ratio (to take in nutrients)
Frog egg – 1mm, can be seen with eye
Most cells are much smaller some 1 micrometer (1/1000 mm)
Prokaryotic vs. Eukaryotic cells – similarities vs. differences
Similarities between Prokaryotes & Eukaryotes- Plasma membrane, Cytoplasm, DNA
Differences- Nucleus(membranenonmembrane bound
Bacillus
rod-shaped bacteria
Coccus
spherical-shaped bacteria
Spirilla or Spirochetes
rod-shaped bacteria that are twisted into a spiral shape
Endosymbiotic Theory
Mitochondria and Chloroplast arose when a large eukaryotic cell engulfed smaller energy producing prokaryotes
organelles
membrane bound compartments found inside the cell
Plasma membrane
is made of a phospholipid bilayer with proteins
Cell wall
maintains the bacteria’s shape (Contains the protein peptidoglycan)
Glycocalyx
outer bacteria layer
If dense- Capsule, If loose- Slime Layer
Cytoplasm
is a semifluid solution made of water, enzymes, and other molecules
Plasmids
extrachromosomal DNA
Ribosomes
are the sites of protein synthesis in prokaryotic cells.
Inclusion bodies
store substances (such as nutrients) inside the cell
Thylakoids
are internal membranes that contain chlorophyll
Nucleus
the membrane bound compartment that houses genetic material
Matrix is referred to as
nucleoplasm
Chromatin
semifluid matrix that contains DNA strands that will later condense into chromosomes
Nucleolus
“little nucleus” made of RNA and protein. Ribosomes are formed here and migrate out the nuclear pores
Nuclear pores
opening in the nuclear envelope that allows ribosomes and RNA out of the nucleus, and certain proteins inside the nucleus
Nuclear envelope
double layer membrane that encloses the nucleus
Chromosomes
rod-like structures of DNA that condense just before the cell divides
Ribosomes
are tiny round structures of protein and RNA. They provide enzymes that allow amino acids to form proteins
Endoplasmic Reticulum (ER)
complex system of membranes, channels and sacs connected to the nuclear envelope (forms vesicles that transports molecules)
Rough ER: contains ribosomes
Smooth ER: no ribosomes
Vesicle
membrane sacs with enclosed molecules
Lysosomes
Membrane bound vesicles produced by the Golgi apparatus
Peroxisomes
similar to lysosomes. Synthesized by free ribosomes.
Vacuoles
are large membrane sacs
Chloroplast
uses solar energy to synthesize carbohydrates (Photosynthesis)
Granum
enclosed compartment of stacked thylakoids
Thylakoids
disk like, surface possesses chlorophyll – formed by a third membrane sac
Stroma
fluid matrix surrounding thylakoids
Mitochondria
break down carbohydrates to produce ATP. (Cellular Respiration)
Inner membrane
Cristae
Cytoskeleton
is made of protein components that run throughout the cytoplasm
Actin filaments
two twisted strands of proteins that provide structure, allow movement
Intermediate filaments
rope-like filaments, provide structural stability
Microtubules
maintain shape in the cell, and acts as tracks along which organelles move. Also direct chromosomes during mitosis.
Centrioles
shortened cylinders that directs the movement of microtubules during mitosis.
Cilia and Flagella
are hairlike projections that move.
hydrophylic
water loving
hydrophobic
water fearing
Phosopholipid bilayer
÷Contains a hydrophylic phosphate head region on the outside of the bilayer
÷Hydrophobic fatty acid tail region on the inside of the bilayer.
scattered throughout the membrane
Proteins
Integral proteins
extend throughout the plasma membrane
Peripherial proteins
occur only in the cytoplasmic side
Glycolipids
carbohydrate chain attached to a phospholipid
Glycoprotein
carbohydrate chain attached to a protein.
differentially permeable
meaning some substances can pass through, while other can’t
Concentration Gradient Example
Oxygen is always being used inside the cell. Therefore the amount of oxygen is always greater outside the cell than inside the cell. (opposite for carbon dioxide)
Bulk transport
allows large particles to enter or exit the cell.
Examples of bulk transport
Exocytosis and Endocytosis
Diffusion
the movement of molecules from areas of high concentration to low concentration
Osmosis
diffusion of water across a differentially (selectively) permeable membrane, due to concentration differences.
Osmotic pressure
the pressure that develops in a system due to osmosis
Isotonic solution
the solute concentration and the water concentration both inside and outside the cell are equal.
Hypotonic solution
cause the cell to swell, or even burst, due to an intake of water.
Hypertonic solution
causes cells to shrink and shrivel, due to loss of water
Cytolysis
bursting of a cell.
Turgor pressure
pressure of a plant cells contents against the cell wall
Facilitated Transport
allows certain molecules to pass in and out of the membrane through carrier proteins along the concentration gradient
Active transport
moves substances from areas of low concentration to areas of high concentration.
What is an example of Active Transport?
The sodium-potassium pump moves sodium (Na+) out of the cell and potassium (K+) into the cell.
Exocytosis
A vesicle fuses with the plasma membrane as secretion occurs
- This is how hormones and digestive enzymes are released
- Vesicles are often produced by the Golgi apparatus
Endocytosis
the cell takes in substances by vesicle formation. The membrane invaginates around a substance and pinches off into a vesicle.
Phagocytosis
when large solid material is taken in the cell.
Ex. White blood cells engulf and destroy debris by lysosomes
Phagein = to eat (Greek)
Pinocytosis
endocytosis when vesicles are formed around a liquid.
Ex. Red blood cells, kidney cells, plant root cells take in liquids this way
Pinein = to drink (Greek)
Receptor-Mediated Endocytosis
substance must bind to a specific receptor before it is taken in.
Extracellular matrix
protective meshwork of proteins and polysaccharides associated with the cells that produce them.
Collagen
structural proteins that resist stretching
Elastin
flexible structural protein
Fibronectin
adhesive protein that connects to integrin
Integrin
¡protein in the plasma membrane that can transmit signals from the extracellular matrix to the inside of the cell.
Proteoglycan
Amino sugar that acts as a signal molecule
Tight junction
the membranes of adjacent cells converge and fuse. (Typically joins cells that form sheetlike layers.)
Desmosome
“rivets” or “spot-welds” skin cells together
Gap junction
tube channels that hold cells together. This lets ions and nutrients move between the cells. (Heart and digestive smooth muscle cells)
Primary cell wall
composed of cellulose (structural carbohydrate) Pectins allow the wall to stretch while the cell grows.
secondary cell walls
form inside the primary cell wall. Contains a greater layer of cellulose
Plasmodesmata
numerous membrane-lined channels that connect plant cells. Allows water and small particles to be shared.
Hypo refers to
less solute in the solution, meaning higher water concentration.
Hyper refers to
more solute in the solution, meaning lower water concentration.
