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Notes based off of the study guide for Dr.Breslins' second unit test about cells.
3 main parts of the Animal Cell:
Nucleus, Cytoplasm (cytosol), Cell Membrane
What is cytology?
The study of cells
Cells vary in size, function, and structure. T/F?
True
All cells are born different. T/F?
False, all cells start out the same but eventually differentiate into specific types of cells.
Function of the cell membrane:
AKA: phospholipid bilayer - consists of phospholipids and embedded proteins. Function: membrane regulates what enters and leaves the cell. Selectively permeable.
What is the nucleus and its function?
“The brain of the cell” - directs cell activities and contains genetic information (dna) in the form of chromatin
Nucleolus - responsible for the production of ribosomes
RNA can exit the nucleus through the nuclear membrane
What is cytoplasm?
Cytoplasm (AKA - cytosol) is the area between the nucleus and the membrane. A lot of cell metabolic reactions occur in this area.
What are the duties and functions of the endoplasmic reticulum?
It is the transport system. It has canals and channels that connect membranes to the nucleus and to organelles within the cell.
Smooth Endoplasmic Reticulum/ Smooth ER is for what:
lipid synthesis
Rough endoplasmic reticulum/ Rough ER does what:
It has ribosomes on the surface, so ribosomes make protein
What do ribosomes do?
Make protein
Function of the golgi apparatus:
Packages and delivers proteins produced by ribosomes, exported by vesicles
Mitochondria (AKA: powerhouse of the cell) function:
Transfers energy from food to a usable form called ATP, this process is called cellular respiration.
What does cellular respiration require:
It requires glucose (food) and oxygen, process done by mitochondria
What happens when the mitochondrial cannot produce enough ATP?
Cells lack energy to perform basic life processes (causing disease or other condition)
Function of lysosomes:
contain enzymes to break down substances: aka “suicide sack”
Effects of lysosome storage disorder:
Brain damage, jaundice, cataracts, enlarged liver, kidney damage, Tay Sachs: progressive deterioration of nerve cells and mental/physical abilities from 7 months-4 years old.
Function of centrosomes (aka: centrioles):
two cylinders; perpendicular, they form a spindle in cell division.
the spindle moves chromosomes during cell division so that each new cell gets the proper amount.
Function of cytoskeleton and what its made from:
made of microfilaments and microtubules, for cell shape and support. cilia and flagella are both involved in movement.
Why is the cell membrane important?
Without it, cells wouldn’t be able to bring in needed materials like food and oxygen, or remove waste. All of these occur at the cell membrane/phospholipid bilayer.
Structure of phospholipids:
Phosphate head (hydrophilic - attracted to water - polar)
Fatty acid tail (hydrophobic - repelled by water - nonpolar)
Arranged as a bilayer, serves as a cellular barries/border
Fatty acid tails/nonpolar hydrophobic tails are impermeable to polar molecules
What does hydrophobic mean
Repelled by water
What does hydrophilic mean
Attracted to water
Why is increasing surface area important?
it can increase the cell’s efficiency of moving substances. Villi (digestive system cell projections) aid in absorbing nutrients with this.
What is passive transport?
a process where no energy is needed and it goes from high concentration to low concentration
Ex: Diffusion or Facilitated Diffusion (high to low)
What is diffusion?
Molecules moving from **high-**concentration areas to **low-**concentration
passive transport
no energy needed
What is facilitated diffusion?
Diffusion through protein channels
no energy needed
passive transport
high to low concentration
in PROTEIN CHANNELS
What is Active Transport?
When cells need to go against (low -→ high) concentration gradient (high to low) they use Active transport.
low to high
protein “pump”
REQUIRES ENERGY = ATP
exocytosis and endocytosis
Is this a good example of what type of Diffusion: Facilitated, Diffusion, or Active Transport? (study this example)
Active Transport
What is exocystosis?
When things exit the cell: secretion
STUDY GUIDE ANSWER:
Exocytosis - large particle leave the cell
What is endocytosis?
Phagocytosis - large solid things (ex: glucose)
pinocytosis - bringing things in from the outside/liquid things (ex: water)
STUDY GUIDE ANSWER:
Endocytosis- large particles enter the cell
Pinocytosis- liquid enters the cell
Lable and study each type of transport - click for labeled answer
Study!
What is osmosis?
The diffusion/movement of water
Study to predict the movement of water based on the solution (hypertonic, hypotonic, or isotonic)
NEED TO KNOW THESE!!!!
Hypotonic cells have:
high water, low solute
freshwater
cell gains water
cell swells, then explodes and bursts
“KABOOM!”
Hypertonic cells have:
low water, high solute
salt water
cell dehydrated and dries out
then dies from no water
“im shrinking, i’m shriveled!”
Isotonic cells have:
mild salt solution
equal solute and equal water concentration
no problems
no net movement, equal flow
cell is balanced
cell is stable
“im perfect!”
Why should we study carbon?
All of life is built on carbon!
How many bonds does carbon form?
They can form 4 stable covalent bonds and can form carbohydrates, lipids, proteins, nucleic acids too!
These cells are usually 72% H2O and 25% Carbon compounds
(??? not too sure about this question)
What are macromolecules?
Smaller organic molecules joining together to form larger molecules
4 major classes:
carbohydrates
lipids
proteins
nucleic acids
What are polymers?
Long molecules are built by linking repeating building blocks in a chain
Dehydration synthesis - adding energy, removing the water
How do you build a polymer?
Using dehydration synthesis - you join monomers by “taking H2O out”
This requires energy and enzymes, takes out the water
adds energy, removes the water
How do you break down a polymer?
Digestion: Hydrolysis
use water/H2O to breakdown the polymer
uses energy and enzymes
adds water, releases energy
Monomer of carbohydrates:
Monosaccharides (C:H:O | 1:2:1)
Monomer of proteins:
Amino acids (CHON, -COOH, -NH2)
Monomer of lipids:
glycerol/fatty acids (C:H:O | greater than 2:1 H:O [carboxyl group])
Monomers of DNA/nucleic acids:
nucleotides (CHONP pentose, nitrogenous base, phosphate)
What are the functions of nucleic acids:
they store information (like genes and blueprints for building proteins, dna→ rna → protein), gather genetic material, and transfer information for the next generations of new cells
What is RNA
RNA is a ribo-nucleic acid, single helix in shape
Are monomers nucleotides? T/F
True
What is DNA?
DNA is deoxyribonucleic acid, double helix in shape
Nucleotide Parts (3):
Nitrogen base - (C-N ring) (a,t,c,g,u part)
Pentose sugar (5C) - ribose in RNA and deoxyribose in DNA
Phosphate (PO4) group
What are purines and list the two examples:
Purines have a double ring N base
Adenine (A) and Guanine (G)
What are pyrimidlines and list the three examples:
Pyrimidlines are single ring N bases
Cytosine (C) and Thymine (T) and Uracil (U)
Purine :: Pyrimidline | What goes with what? (A,G,C,T)
A::T (2 H bonds)
G:: C (3 H bonds)
Structure of proteins:
20 different amino acids/monomers
polypeptide/polymers, large and complex molecules, complex 3-D shape
Function of proteins:
literally almost everything
study list
know they are the most structurally and functionally diverse
structure of amino acids:
central carbon
amino group
carboxyl group (acid)
R group (side chain) (1 of the 20)
Protein: List the 4 levels of folding and their functions
Primary structure (1)- order of amino acids in chain, sequence determined by DNA/gene, slight change can change function and structure!!
Secondary structure (2)- local folding, short sections of polypeptides, H bonds, alpha helix or beta pleated sheets (3-D structures in sections)
Tertiary structure (3)- whole protein/molecule folding, hydrophobic, h bonds and ionic bonds, disulfide bridges
Quaternary structure (4)- not all proteins, only ones with multiple polypeptide chains, hydrophobix interactions
What happens when you unfold a protein? (protein denaturation)
temperature, pH, and salinity can disrupt H, ionic bonds, or disulfide bridges
in 2 and 3 structure it alters their shape
denaturation destroys functionality, some proteins can return to their functional shape, others cannot
What makes a carbohydrate..a carbohydrate?
any molecule that has the elements C:H:O in a 1:2:1 ratio.
Simple vs complex carbohydrates:
simple: made up of one or two monomers
complex: long polymers (aka: polysaccharides, good fo r storing energy)
Monosaccharides consist of:
one monomer subunit (ex: sugar glucose: C6H12C6
disaccharides consist of:
two monosaccharides: ex: sugar sucrose/table sugar - glucose +fructose= sucrose
Plants form what?
starch
Animals form what?
glycogen
Where is cellulose found in plants?
their cell walls
Where is chitin found in many invertebrates and cell walls of fungi?
in the exoskeletons
Function of lipids:
long term energy storage
concentrated energy
cushions organs
insulates body
Lipids make polymers T/F?
F - false, they do not form polymers. Big molecules make smaller subunits, not a continuing chain.
Structure of lipids/fats:
glycerol + a fatty acid
the fatty acid = the long HC “tail” with COOH (carboxyl group) “head”
can be seen in dehydration synthesis
Is the long HC chain of lipids/fats Polar/non-polar and hydrophilic/hydrophobic?
non-polar
hydrophobic
Triaglycerol has:
3 fatty acids linked to glycerol
ester linkage - between OH and COOH
Cholesterol is a four ring structure? T/F
T - helps keep cell membranes fluid and flexible
its in the animal cell membranes and a precursor of all the other steroids
high levels of cholesterol in blood may contribute to cardiovascular disease
Function of cholesterol:
keeps cell membranes fluid and flexible
precursor for steroids
important component of cell membrane
Structure of steroids:
4 fused C rings + (x)
x can be any functional group
steroids are formed from cholesterol
different functional groups → different cellular functions
List the stages of a cells life cycle:
Interphase = growth phase (G1, S, G2)
Mitosis = nuclear division
Cytokinesis (cell division)
study diagram
What happens in interphase? (G1, G0, S, G2)
G0 - non-dividing phase, growth
G1 - growth phase 1, preparation for DNA Synthesis
S - DNA replication: DNA must be copied and replicated ensuring the new cells contain the proper amount of dna
G2 - Preparation for Mitosis, growth
Be able to recognize parts of PMAT in the onion root:
Study! You don’t have to know pre- and mid- just know what the phases look like
What does PMAT stand for? What are the stages of Mitosis?
PMAT - prophase, metaphase, anaphase, telophase
Mitosis - Interphase (1), Prophase (2), Metaphase(3), Anaphase (4), Telophase(5), (Cytokinesis (6))
What happens in Cytokinesis?
Division of the cytoplasm happens to form 2 new daughter cells
organelles are divided
daughter cells are genetically identical
then cells return to interphase to keep replicating!
Chromatins vs Chromosomes
Chromosomes are made up of a DNA-protein complex called chromatin - study diagram for parts
What happens in prophase?
visible chromosomes (aka - chromatids)
centrioles migrate to the poles
nuclear membrane disappears
nucleolus disappears
spindle forms
What happens in metaphase?
chromosomes line up on the equator
and the spindle attatches
What happens in Anaphase?
chromatids seperate at the centromere and move to opposite poles
think of A for anna in frozen being pulled away bc of her sister elsa
What happens in Telophase?
chromosomes disappear - chromatin
nuclear membrane reforms
nucleoli reappears
spindle disappears
centrioles duplicate
When does differentiation occur?
As cells multiply and organisms develop and grow
Stem cell → then to whatever is needed in the organism
stem cells can be many different types of cells, each with their own distinct function
How is cancer caused?
By uncontrolled cell division. In normal cells, cell division eventually stops. With cancer cells, their DNA is damaged and never had division stop.
How are chromosomes inherited?
1 from mom, one from dad
There are 23 pairs of human chromosomes T/F?
True
What phase of MPAT is this?
Telophase
What phase of MPAT is this?
Anaphase
What phase of MPAT is this?
Metaphase
Note 
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