Cells Anatomy & Physiology

What do you think situs inversus is? Mackenzie, at 4 years old, was diagnosed with pneumonia. Her parents were worried, it seemed that Mackenzie was always sick. She always had a runny nose and had frequent ear infections. The diagnosis of pneumonia also revealed something else - Mackenzie had a condition known as situs inversus. What do you think situs inversus is? 2. How might Mackenzie’s condition be related to cell disfunction? This mini case is based on a real person (Source), images are stock images from morguefile.com

Cells vary in SIZE and STRUCTURE Depends on what they do

Cell Membrane is selectively permeable Cytology = the study of cells All Animal Cells have 3 main parts Nucleus Cytoplasm (cytosol) Cell Membrane Cell Membrane is selectively permeable

Lipid bilayer (phospholipids) make up the membrane with proteins embedded to help regulate what comes across the membrane

Given Mackenzie’s history of illness, sniffles, and ear infections, doctors wanted to rule out cystic fibrosis. A simple “sweat test” is used to diagnose CF. Examine the image. Why is CF considered a disorder related to the cell membrane. Could CF have caused Mackenzie’s symptoms? The sweat test showed that Mackenzie did not have extra chloride in her sweat. Does this mean that she does not have CF? Could there be another cause for Mackenzie’s frequent infections?

The cytoplasm (cytosol) is the area between the nucleus and the membrane. Many of the cell’s metabolic reactions occur in this area. Do you remember what metabolism is?

ORGANELLES-  "little organs" within the cell that perform specific functions The nucleus is to the cell what the __________is to a person. The cell membrane is to a cell what the ________ is to a person.

ENDOPLASMIC RETICULUM Transport system; canals and channels that connect membrane to nucleus and to organelles within the cell Function = transport system Smooth ER (lipid synthesis) Rough ER (contains ribosomes for protein manufacture)

Golgi Apparatus Flattened membranes; Function = package and delivery of proteins produced by the ribosomes Proteins are exported in vesicles

Mitochondria ( The “powerhouse” of the cell ) Chemical energy from food is converted to a useable form (ATP) -- process is called Cellular Respiration What does respiration have to do with metabolism?

Lysosomes - contain digestive enzymes to break down substances (“suicide sac”) Enzymes break down substances in the cell, such as food or worn out cell parts, even bacteria. Remember the video on how beans become farts? What is the enzyme in this image and how do you know? What organ is your body is most like the lysosome?

Centrosome – two cylinders, centrioles, that sit perpendicular During cell division, the centrioles separate and form a spindle. The spindle moves chromosomes during cell division so that each new cell gets the proper number.

CYTOSKELETON made of microfilaments and microtubules which maintain shape and functions in movement Cilia & Flagella

Doctors wanted to test Mackenzie for a disorder called “PRIMARY CILIARY DYSKINESIA” This disorder causes cells to not create normal cilia. Cells scraped from the sinuses showed an irregularity in Mackenzie’s cilia. What is different about this cilia? Why would problems with cilia cause pneumonia, ear infections, and a constant runny nose?

NUCLEUS - (the “brain” of the cell) Directs cell activities (the “brain” of the cell) Contains genetic information (DNA) in the form of chromatin Also contains a nucleolus – makes ribosomes Has tiny pores in the nuclear membrane is where RNA can exit the nucleus

What about the situs inversus? Mackenzie can live with PCD, but she will always have a cough and deal with lung and ear infections. What about the situs inversus? Doctors have warned her parents that when she gets older, she may have trouble conceiving a child and is at risk for an ECTOPIC pregnancy. What role does cilia play in reproduction?

- See more at: http://www.marlafoundation.org/#sthash.Sa4tGqp1.dpuf About Situs Inversus It has been indicated that Situs effects .01% of the human population.  It is also been calculated that 1 in 10,000 people have this anomaly.  Therefore, if the human population totals 8 billion, there are 800,000 people who have Situs Inversus Totalis. - See more at: http://www.marlafoundation.org/#sthash.Sa4tGqp1.dpuf

It is believed that the motion of cilia may play a part in determining the placement of organs within the thoracic and abdominal cavities. In the absence of ciliary motion, organ placement becomes a random event, giving each affected embryo a 50/50 chance of having typical or atypical placement.

1. What part of the cell is most like the stomach? More analogies 1. What part of the cell is most like the stomach? 2. What part of the cell is most like your circulatory system? 3. What part of the cell is most like your brain? 4. What part of the cell is most like your bones? 5. What part of the cell is most like your skin? Super Difficult Bonus Question Which part of the cell do you think is the most responsible for maintaining homeostasis? subjective question, could be either the cell membrane or the mitochondria

Movement of Substances Across the Membrane Cells - Part 2 Movement of Substances Across the Membrane Cells must bring in materials, like food and oxygen and remove wastes. These processes occur at the cell membrane. PHOSPHOLIPID BILAYER

Cells are limited in size by the surface area (membrane) and volume (insides) ratio.

Increasing surface area can increase the cell’s efficiency moving substances. Cells of the digestive system have projects called villi that aid in absorbing nutrients.

Diffusion - molecules tend to spread out; moving from areas of high concentration to low concentration This process requires no energy, it is called PASSIVE TRANSPORT Diffusion Animation

Movement of Substances Through the Membrane Diffusion - molecules tend to spread out Facilitated Diffusion - uses proteins as passageways Diffusion Animation

SALT SUCKS OSMOSIS - the diffusion of water Hypertonic Hypotonic Isotonic SALT SUCKS

Osmosis Animation

Active Transport - requires energy (ATP) Exocytosis - secretion; things exit cell Endocytosis (phagocytosis & pinocytosis)

A. Interphase = growth phase, *differentiation occurs Cells - Part 3 The Life Cycle of the Cell A. Interphase = growth phase, *differentiation occurs B. Mitosis = nuclear division C. Mitosis is followed by cytokinesis (cell division) The steps of mitosis ensure that each new cell has the exact same number of chromosomes as the original

Interphase • Prophase • Metaphase • Anaphase • Telophase IPMAT

The structure of a chromosome

1. chromosomes visible (chromatids) 2. centrioles migrate to the poles 3. nuclear membrane disappears 4. nucleolus disappears 5. spindle forms

chromosomes line up on the equator, spindle attaches

chromatids separate at the centromere and move to opposite poles

1. chromosomes disappear • chromatin 2. nuclear membrane reforms 3. nucleoli reappears 4. spindle disappears 5. centrioles duplicate

- division of the cytoplasm to form 2 new daughter cells - organelles are divided - daughter cells are genetically identical Cells return to interphase

DIFFERENTIATION occurs as cells multiply and organism develops and grows

Cancer: caused by uncontrolled cell division

CLASS QUIZ Name the phases starting at the top.

Name the phase Identify X Identify Y

5. Name the phase

6. Name the structure

Name the structure What is its function?

10. What will happen to the baggie in the hypertonic solutions? 9. Which beaker(S) contains a solution that is hypertonic relative to the bag      A                     B                   C                   D                    E 10. What will happen to the baggie in the hypertonic solutions?