Anatomy Unit 2: Cells - Dr.Breslin - SWCTA 23-24

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?

Usin**g 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