Study guide 1 Flashcards
What is physiology?
Human structure and function the biology of the human body.
What was Aristotle’s contribution to physiology?
Gave rise to the terms physician and physiology
What did Hooke do?
made improvements to the compound microscope. Invented specimen stage, illuminaotr coarse and fine controls. First to see and name “cells”
Who is Anton van Leeuwenhock
Anton van Leeuwenhock: invented a simple (single-lens) microscope with great magnification to look at fabriics (200X)
What are tissues composed of?
Tissues comprise a group of similar cells that come together and function as a unit. (epithelial, connective, nervous, muscular.)
What are organs composed of?
Organs are two or more tissue types that come together to carry out a particular function as a system.
How are organs different from an organ system?
organs come together to form an organ system.
what are the 11 types of organ systems?
integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, urinary, digestive, reproductive.
What is reductionism?
the idea that components are not completely independent. In order to understand the whole organism you must look at all the parts.
What is holism?
the idea that components are not completely independent. In order to understand the whole organism you must look at all the parts in sum total.
Is everybody structured the same way?
No two humans are alike (not even twins).
The anatomy book show the most common organization. This would match what percentage of people?
present in 70% of people
What does the palmaris longus muscle demonstrate?
Demonstrates that not all people are the same.
What is situs inversus?
Situs inversus is when the organs in your chest and belly develop in a reversed position of normal anatomy.
Can someone survive situs inversus?
yes, you can typically live a normal life even with this condition.
Is everybody physiologically the same? What can contribute to the differences we see?
Not everyone is the same. Sex, age, diet, weight, physical activity, genetics and environment all play a role in how people function.
If we don’t recognize that variation in physiology exists what can happen?
failure to consider variation can lead to overmedication of the elderly or medicating women on the basis of research done on men.
What are some characteristic shared by all living organisms?
Organization, cellular composition, metabolism, responsiveness, movement, development, reproduction, evolution, homeostasis.
CHROMED RM
What did the “men in the oven” experiment help demonstrate?
it helped show that homeostasis occurs in all living things and regulates body temperature through sweating.
What is homeostasis?
Its the ability to detect change, activate mechanisms that oppose it, and thereby maintain relatively stable internal conditions.
Negative feedback loops:
body temperature, if it is too warm vessels dilate in the skin and sweating begins. If too cold, vessels in the skin constrict and shivering begins. (like a thermostat)
Positive feedback loops:
leads to greater change in the same direction. The feedback loop is repeated changes produce more change. Child birth, blood clotting, protein digestion.
What are the three parts of the cell theory?
- Every living organism is made up of one or more cells.
- The smallest living organisms are single cells, and cells are functional units of multicellular organisms.
- All cells arise from preexisting cells.
What four criteria are used to define a cell
- membrane bound phospholipid bilayer
- can divide and reproduce
- gathers raw material from the environmet to use as building blocks/food
- heritable genetc code
What size is a “typical” cell in the human body?
20 um
can we see any cells with the naked eye?
yes, the human egg cell
How are eukaryotic cells different from cells in the other domains?
They have a membrane-bound nucleus that houses their DNA and a variety of other membrane-bound organelles that compartmentalize cellular functions.
What is the plasma membrane?
Plasma membrane/ cell membrane: a thin, flexible barrier that surrounds every cell, separating the cell’s interior from the external environment and controlling what substances can enter and exit the cell.
What % of the plasma membrane is protein?
98% of membrane molecules are lipids and 2% are proteins.
What % of the plasma membrane are phospholipids?
75% of the membrane lipids are phospholipids
Is the plasma membrane rigid?
No it is soft and flexible
Are phospholipids distributed evenly in the plasma membrane
No it is not evenly distrubuted
What are the four most abundant phospholipids?
PS=phosphatidylserine, PE=phosphatidylethanolamine, PC=phosphatidylcholine, and S=sphingomyelin
What are glycolipids?
lipids that have a carbohydrate attached to them by a glycosidic bond
Why are glycolipids important to a cell?
they play a crucial role in maintaining cell membrane stability, facilitating cell recognition, and acting as receptors for cell signaling.
Microvilli are
fingerlike projections from the cell surface, best developed in cells specialized in absoprtion.
Primary cilium
single, non motile primary cilium found on nearly every cell. Helps with balance in the inner ear.
Motile Cilia
Hair like structures filled with microtubules and proteins. Move mucus layer across cell surface.
Flagella
long whip like structures
found only in one cell in humans (sperm)
Used for swimming
Pseudopods
continually changing extensions of the cell that vary in shape and size.
Used for cellular locomotion, capturing foreign particles.
What is the cytoplasm?
The space between the nucleus and the plasma membrane. It is composed of organelles and the cytosol.
Which organelles have membranes?
endoplasmic reticulum, Golgi apparatus, nucleus, mitochondria, lysosomes, endosomes, and peroxisomes
NEMGL
What organelles have more than one membrane?
Nucleus, mitochondria, and chloroplasts
Why do certain organelles have more than one membrane?
because this compartmentalization allows for distinct internal environments within the organelle,
Nucleus:
- enclosed by two phospholipid bilayers that are perforated by nuclear pores
- houses genetic material
- synthesis of ribosomes
Smooth ER
- enclosed by a single phospholipid bilayer
-lacks ribosomes - cisterns more tubular and branching
- synthesizes new lipids
SYNTHESIZES NEW LIPIDS, SEQUESTERS AND RELEASES CA2+ IONS
Rough ER
- enclosed by a single phospholipid bilayer
- very large organelle
- synthesizes proteins that are packaged in other organelles or secreted from the cell.
- one membrane
Ribosomes
- not enclosed by a lipid bilayer
- small granules of protein and RNA
- They ‘read’ coded genetic messages
-assemble amino acids into proteins specified by the code
golgi apparatus
- enclosed by a single phospholipid bilayer
- sorts, tags, packages, and distributes the proteins and lipid from the ER
- like a post office
Mitochondria
- enclosed by two phospholipid bilayers
- Organelles are specialized for synthesizing ATP and it also stores CA2+ ions
Proteasomes
- non membranous
- break down the unwanted proteins in the cells
Centrioles
- non membranous
- help organizes microtubules and determine the location of organelles and the nucleus within the cell.
Ribosomes
- nonmembranous
- cellular structure that synthesizes proteins by translating messenger RNA into amina acids
How do organelles work together to produce proteins?
First transcribing DNA into mRNA in the nucleus, then transporting the mRNA to ribosomes where the mRNA is translated into a polypeptide chain.
Kartagener’s syndrome
cilia unable to beat properly. Situs inversus, respiratory issues.
Treacher Collins
results from a mutation in genes that code for proteins essential for the formation of ribosomes
affects the face and not the life span
How thick is the plasma membrane? Does it vary in thickness?
It is 5nm thick and it can vary in thickness depending on the composition of its lipids and proteins.
How are phospholipids structured?
They are considered amphipathic (having both hydrophilic and hydrophobic parts) the heads are hydrophilic which means they love water and the tails are hydrophobic which means they fear water. This is important because it allows us to form a stable bilayer.
How does the saturation or a double bond in the phospholipid tail influence the membrane?
Increases the fluidity of the membrane by introducing “kinks” in the chain preventing the phospholipids from packing tightly together.
Hydrophilic molecules
they love water
or polar molecules such as acetone from favorable electrostatic interactions with water molecules, which are also polar. Polar molecules readily dissolve in water (they are water soluble)
Hydrophobic molecules
or nonpolar molecules, such as 2 methyl propane cannot form hydrogen bonds with water molecules. Such molecules therefore aren’t soluble.
Why is cholesterol important to the cell membrane and what does it do?
Cholesterol is said to not reduce the fluidity of the lipid bilayer, but it is thought to render the bilayer less permeable to small, water-soluble molecules (cholesterol is hydrophobic)
What are lipid rafts and what purpose do they serve?
Microdomains or subdomains within the phospholipid bilayer. Hot spots for signal transduction.
A hydrophilic molecule is also necessarily….
lipophobic
A hydrophobic molecule is necessarily….
lipophillic
What determines how easily a molecule can get through the membrane?
Its size, polarity, and charge can generally help or hinder molecules through the membrane.
Are there any molecules that can get through the membrane unassisted by transport proteins?
Small nonpolar molecules like oxygen (O2) and carbon dioxide (CO2) can pass through a cell membrane without the assistance of transport proteins.
What are the different types of transport proteins found in the membrane?
- ion channels
- pumps (aka ATPases)
- Exchangers (aka Antiporters)
- co transporters (aka symporters)
- uniporters
CUPIE
What are ion channels used for? can they be gated?
Io channels are transmembrane proteins that conduct ions at high rates. They contain an aqueous pore that is shielded from contact with the bilayer. They possess gates that can be opened or closed.
How selective are ion channels and how fast can ions travel through these channels?
They may be highly selective for a particular ion species. Flux rate: 10^7 to 10^8 ions/sec.
What happens during passive transport?
During passive transport substances move across a cell membrane from an area of high concentration to an area of low concentration without requiring any energy from the cell.
Electrical gradients only apply to which molecules?
Electrical gradients apply to charged molecules, specifically ions.
What is active transport?
During active transport molecules or ions move across a cell membrane from a region of lower concentration to a region of higher concentration (against the concentration gradient).
How do primary active transport and secondary active transport differ from each other?
Primary active transport directly uses energy from ATP to move molecules against their concentration gradient, while secondary active transport uses the energy stored in an existing electrochemical gradient, created by primary active transport, to move molecules against their concentration gradient.
What type of transport protein is GLUT?
Glucose transporters (GLUTs) are a type of membrane protein that facilitates the transport of glucose and other substances into and out of cells. And its facilitated diffusion.
What type of transport protein is the Na+/K+ pump?
Na+/K+ pump is an ATPase enzyme that cleaves ATP into ADP and attaches a phosphate molecule (P) to itself to drive changes in its shape (autophosphorylation). And it’s active transport.
What type of transport protein is the Na+/glucose symporter?
Na+/glucose symporters are secondary active transporters.
What is digoxin?
Digoxin is found in foxgloves. It’s a cardiac glycoside
What does digoxin do?
Digoxin is used to make drugs to treat congestive heart failure. They affect cardiac function by inhibiting the pump. Results in increasing intracellular resting. Increases the force of systolic contractions
