Unit 1 Lecture Flashcards
What is the definition of anatomy?
The study of body structures
What is the definition of physiology?
The study of body functions
Structure without function is considered _____
Empty
Function without structure is considered ______ ______
Without mechanism
What are the five characteristics of living systems?
A) Metabolism B) Responsiveness C) Movement D) Growth and Differentiation E) Reproduction
What is the definition of metabolism? What are the two types?
The sum of all chemical processes that occur in the body. The two types are catabolism and anabolism.
What is the definition of catabolism?
The breakdown of large molecules into small ones
What is the definition of anabolism?
The construction of larger molecules from small ones.
What is the definition of responsiveness?
The ability to respond to change in the internal or external environment. Ex. Sensors sense heat on skin, integrators and controllers in the brain notify brain’s hypothalamus, effectors in the integumentary system start to respond by sweating
Discuss movement as a characteristic of living systems.
It occurs at any structural level in the body, an organ, a cell or cell component
Discuss growth and differentiation as characteristic of living systems.
Growth refers to the increase in number or size of cells or the material found between cells. Differentiation refers to the specialization of cells for a specific function.
What is the definition of reproduction as a characteristic of living systems?
Formation of new cells and the formation of new individuals.
What are the levels of structural organization from smallest to most complex?
1) Chemical level 2) Cellular level 3) Tissue level 4) Organ level 5) Organ system level 6) Organismic level
How do we measure metabolism?
Measure amount of produced heat
What is a main function of metabolism?
It produces heat
What is the chemical level of structural organization?
The atomic and molecular level
What is the cellular level of structural organization?
Smallest living unit of the body
What is the tissue level of structural organization?
Groups of cells and the materials surrounding them that work together on one task
What is the organ level of structural organization?
qGrouping of 2 or more tissue types into a recognizable structure with specific functions
What is the organ system level of structural organization?
Collection of related organs with a common function
What is the organismic level of structural organization?
One living individual
Who coined the term homeostasis?
Famous French physiologist Claude Bernard
What was Claude Bernard’s idea about homeostasis?
The constancy of the internal environment is the condition for a free and independent life.
What are the 5 steps of the scientific method?
1) Observation 2) Hypothesis and Prediction 3) Experimental testing 4) Analysis and conclusion 5) Development of a new hypothesis
What is an example of an observation?
In the face of big changes in environmental temperature, body temperature seems to be constant
What is a hypothesis?
It is a tentative answer to the question posed. It is not the question itself.
What is an example hypothesis?
Body temperature is constant with time
What is the main question you are asking yourself in the analysis and conclusion phase of the scientific method?
Do the data support the hypothesis?
What are controlled conditions in our body?
Temperature, Water content, Carbon dioxide level, and blood sugar level. Which are controlled by the nervous system and hormones
What is the definition of homeostasis?
Homeostasis is the condition in which the body’s internal environment remains relatively constant within physiological limits
What are examples of physiological limits?
Heat, moisture, pressure, chemical composition, etc.
Discuss physiological limits and viability with the Controlled Condition/ Viability curve
The body has a threshold that keeps you alive. The body’s physiological limits is a range that is safe the curve basically explains how viable to life you are when the physical limits are exceeded or maintained. When your physiological limits are either very high or very low, your viability for life is low. The shape is a bell curve.
Discuss the Maintenance of Homeostasis Negative Feedback graph.
The blue lines are the physiological limits so between them is the normal range. The x-axis is time and the red line is controlled conditions such as our body temperature. It doesnt stay constant, it fluctuates based on external stimuli effecting receptors which trigger effector sweat glands for example to give off a response of sweat to lower the body temperature.
What is a set point in homeostasis?
The stable mean around which a controlled condition varies
What is the most common feedback loop in our body?
Negative feedback loops are much more common in human bodies.
Explain the difference between negative and positive feedback loops.
Positive feedback system continually reinforces a change in a controlled condition, some event outside the system must shut it off, whereas negative feedback system, by contrast, slows and then stops as the controlled condition returns to its normal state.
Example of a positive feedback loop.
Example of negative feedback loop.
Characteristic of negative feedback loop.
- Original stimulus reversed
- Most feedback systems in the body are negative
- Used for conditions that need frequent adjustment
- Body temperature, blood sugar levels, blood pressure
Characteristics of positive feedback loop.
- Original stimulus intensified
- Seen during normal childbirth
Positive feedback loop actual loop graph thing.
What is the definition of ‘steady-state’?
A ‘constant’ state maintained through time.
What is the definiton of equilibrium?
A constanr state achieved without energy expenditure
T or F: Equilibrium is a special case of Stead-State
True
The maintenance of _____ is energy expensive.
homeostasis
Definition of homeostasis
The condition in which the body’s internal environment remains relatively constant with physiological limits
What is the chemical level of organization?
The simplest (most basic) level of biological organization.
A constant state achieved without energy is called…
Equilibrium
Why is the number of protons and electrons important to a particle?
Defines in the particle has a net neutral, positive, or negative charge
What is a positive ion?
Cations
What is a negative ion?
Anion
What are the major element in biology from most to least abundant
1) Oxygen 65%
2) Carbon 18%
3) Hydrogen 10%
4) Nitrogen 3%
5) Ca, Na, K, Cl, P 4%
Define an element
Substance that cannot be split into simpler substances by ordinary chemical means
Define molecule (compound)
Assemblage of atoms (same or different) held together by chemical bonds
What are two ways of bonding within a molecule?
Covalent (sharing electrons) and ionic (use attractive force of electrical charge/ transfer of electrons)
How is stability of atoms influenced?
By the number of valence electrons
Can sharing of electrons in covalent bonds be equal and unequal?
Yes, when it is unequal it is a polar covalent bond but when it is equal it is a polar valent
What happens to the atom to loses/gains electrons in ionic bonds?
The atom donating electrons becomes a cation and the atom gaining electrons becomes an anion. Aka: they have more or less negative charge with more or less electrons than their neutral state
Why does hydrogen bonding occur?
Poles of slightly negative charges on F, O, N will attract the poles of another slightly positive H that will then stabilize the structure by H-bonding
Discuss H-bonding
- Weak bond
- Many hydrogen bonds stabilize structure so it is overall strong
Breaking bonds _____ energy
Requires
making bonds ______ energy
releases
Metabolism is the result of what regarding chemical bonds?
It is the result of cell manipulation of energy in chemical bonds
Define potential energy
Chemical energy stored in chemical bonds
Define kinetic energy
Energy of movement
Define catalyst
Compounds that make reactions go faster by reducing the activation energy required to get the reaction started (breaking bonds)
What is another word for biological catalysts?
Enzymes
Draw a potential energy vs progress of reaction graph with a catalyst
What catalyzes glucose + ATP -> glucose-6-P + ADP
Hexokinase
Define solution
Mixture of two or more components
What types of molecules can interact with water?
Molecules with polar or ionic bonds
How does water solvate particles?
Water surrounds each molecule which solvates and holds it in solution
What is the concentration ratio?
Moles/liter or amount of compound/unit of volume
Avogadros number
6 x 10^23 particles
What is pH
The concentration of hydrogen ions H+ which is a very reactive proton that tends to bind to some atoms and comes off others. It adds or substracts electrical charge and thereby influences structure and function by molecules
Shorthand way of noting H+ concentration
pH = -log[H+]
pH = -log10^-7 =7
Discuss the pH scale
pH of 0 is very acidic with a more concentrated amount of H+, pH 14 is very basic (alkaline) and has a more concentrated amount of OH+
How is the pH of body fluids maintained?
Within narrow ranges through the influence of ‘buffering systems’
How do buffers work and what is their purpose?
They function to convert strong acids or bases into weak acids or bases. They do so by removing or adding protons (H+)
What are the four important organic compounds to the human body and what do they all have in common?
1) Lipids C+H
2) Carbohydrates C+H+O
3) Proteins C+H+O+N
4) Nucleic acid C+H+O+N+P
THEY ALL CONTAIN CARBON
Discuss lipids
Long chains containing C+H+O. They are typically used for structure or insulation. Some can be hormones like cortisol, estrogen, or testosterone
Discuss carbohydrates.
Contain C+H+O and are typically in a ring shape linked to other rings. They are used for energy. Ex. Glycogen
Discuss proteins
Have the same basic structure C+H+N+O with an alternating side chain. They are amino acids and bond with peptide chains.
Discuss nucleic acids
Are DNA, RNA. They are in charge of protein synthesis or genetic material. They consist of nitrogenous bases, five‐carbon (pentose) sugars, and phosphate groups. In DNA, the bases are held together by hydrogen bonds.
What are the four components of the cell theory?
1) Cells are the ‘building blocks’ of animals and plants
2) Cells arise from pre-existing cells
3) Cells are the smallest unit having all the functions of the living systems
4) Homeostasis of higher levals of biological organizarion arises from cordinated activity of cells
Define plasma membrane
Interaction surface between a cell and the workd outside of it
Define nucleus
Contains the genetic material of the cell
Define cytoplasm
Everything betweent the membrane and the nucleus
- Intacellular fluid (cytosol)
- Subcellular structure with specific functions (organelles)
What are the two categories of organelle?
1) Membranous
2) Non-membranous
What are some membranous organelles?
- Endoplasmic reticulum
- (nucleus)
- Mitochondria
What are some non-membranous organelles?
- Cytoskeleton
- Ribosomes
What are the three main components of the plasma membrane composition?
1) Lipid (the principal membrane lipid is pospholipid)
2) Protein
3) Carbohydrate
What does it mean that a phospholipid is an amphipathic molecule? Why is this important?
It means that the phospholipid has a polar ‘head group’ region and non-polar ‘tail’ region and because of this phospholipids are capable of spontaneous ‘self-assembly’
Explain the different types of self assembly for phospholipids
Micelle - one ball of phospholipids with their non-polar tails all facing the inside and their polar heads facing the outside creating a membrane.
Liposome - the structure of a plasma membrane where there are two layers of phospholipids and their tails face each other. It somewhat looks like a sandwhich when you lay it down flat: Phospholipid polar head, non-polar tails, non-polar tails, polar heads. This shape in particular is rolled up into a ball like the micelle.
What are the six main types of membrane proteins?
- Ion channel (integral)
- carrier (integral)
- Receptor (integral)
- Enzyme (integral and peripheral)
- Linker (integral and peripheral)
- Cell identity marker (glycoprotein)
What is a membrane protein?
Confers different functionality (physiology) upon different membranes in cells
What is an ion channel?
What is a carrier in the plasme membrane?
What is a receptor in the plasma membrane?
What is an enzyme in a plasma membrane?
What is a linker in the plasma membrane?
What is a cell identity marker?
These are often carbohydrates.
What are proteins comprised of?
A linear sequence of amino acids.
What is the primary sequence of protein?
A sequence of a chain of amino acids called a peptide chain.
What is the secondary protein structure?
Occurs when the sequence of amino acids are linked by hydrogen bonds. The structures can either be pleared sheets or alpha helix (spiral)
What is the tertiary protein structure?
Occurs when certain attractions are present between alpha helices and pleated sheets.
What is the quaternary protein structure?
Is a protein consisting of more than one amino acid chain.
What are the two types of membrane proteins?
- Integral proteins
- Peripheral proteins
What are integral proteins?
- Extend into or completely across cell membranes
- they are amphipathic with hydrophobic portions ‘hiding’ among the phospholipid tails of the lipid bilayer
What are peripheral proteins?
-Attached to either inner or outer surface of cell membrane and are easily removed from it
What is true from the fluid mosaic model of the cell membrane regarding protein movement?
Membrane proteins are free to move laterally throughout the cell membrane.
How do we know that membrane proteins move within the plane of a ‘fluid’ lipid bilayer? What was the experiment?
OBSERVATION:
- Phospholipids display rapid lateral diffusion in membrane bilayers
- Integral membrane proteins reside in the lipid bilayer
QUESTION:
Can integral membrane proteins diffuse laterally in the lipid bilayer?’
HYPOTHESIS:
Integral membrane proteins diffuse laterlly in the plane of the plasma membrane
TESTING:
‘FRAP’ Flourescence Recovery After Photobleaching
ANALYSIS:
After bleaching an area of the membrane, fluorescently tagged proteins laterally difused into bleached areas.
What is passive transport?
-Substances move down their concentration gradient (high to low concentration) without energy input.
What is active transport?
Substances move against their concentration gradient (low to high concentration) using energy from the cell (ATP)
What is true of diffusion and concentration proportionality?
Net diffusion is proportional to concentration gradient
How fast does diffusion occur?
Diffusion occurs rapidly over short (cellular) distances; but slowly over long (‘organismic’) distances
To diffuse into (or out of) a cell, solutes must ….
…enter the lipid bilayer
- Hydrophilic (solutes) can’t
- Hydrophobic (non-polar) solutes can
What moves in diffusion?
The solute
What moves in osmosis?
The solvent through semi-permeable membranes
Define simple diffusion
A type of passive transport involving hydrophobic substances like: gasses (O2, CO2), fatty acids, seroid hormones, fat soluble vitamins can go through the plasma membrane at any time without a channel or carrier protein.
Define osmosis in plasma membranes
A type of passive transport of water through channels called aquaporins across the membrane.
What can use channel mediated facilitated diffusion?
Ions like K+, Na+, Ca2+, and Cl-
What can use carrier mediated facilitated diffusion?
Glucose, fructose, galactose, and some vitamins
What solutes permeate more rapidly? Hydrophobic or hydrophilic?
Hydrophobic solutes
Define osmosis in semipermeable membranes
Net flow of water
(across a semipermeable membrane) in response to a gradient in the chemical activity of water
How will the U-tube look at equilibrium?
How do we measure osmostic pressure?
We restore starting conditions from equilibrium conditions by applying pressure to the raised (high solute concentration) side until the water is forced through the semipermeable membrane to even out the water on both sides. The applied pressure = osmotic pressure
How do carrier-mediated proteins determine what they let through?
1) Saturability
2) Selectivity
Each transport protein can ‘accept’ a limited range of chemical structures as substrates
What are two categories of carrier-mediated transport?
- Facilitated diffusion
- Active transport
Define primary active transport
Energy derived from hydrolysis of ATP changes the shape of the carrier protein and pumps the substance across the membrane against the concentration gradient (the Na+/K+ pump is a good example)
Define secondary active transport
Energy stored in the Na+ or H+ gradient is used to move other substances against their concentration gradients. *Uses ion gradients
Three examples of bulk transport
Endocytosis (envagination of particles into the cell in a vesicle), exocytosis (vesicle travels to the cell and combines itself to the cell wall to let out particles), and transcytosis (basically endocytosis through a membrane to the lumen on epithelial cells)
Explain the Na+/K+ pump
3Na+ ions removed from cell as 2K+ brought into cell, with 1 ATP hydrolyzed
Antiporters vs. Symporters
What are the two types of organelles?
1) Membranous
2) Non-membranous
What are membranous organelle examples
- Mitochondria
- Endoplasmic reticulum (ER)
- Golgi complex
- Nucleus
What are non-membranous organelle examples?
- Cytoskeleton
- Ribosomes
- Proteasomes
What three things is the cytoskeleton made of?
1) Microfilaments
2) Intermediate filaments
3) Microtubles
What are microfilaments and what are their functions?
They are strands of protein (actin) that connect organelles to membranes and they influence cell motiity and shape. They are involved in muscle contraction, cell division, and cell locomotion, such as occurs during the migration of embryonic cells during development, the invasion of tissues by white blood cells to fight infection, or the migration of skin cells during wound healing.
What are intermediate filaments and their function?
They are keratins and they are there for structural stability; they help stabilize the position of organelles such as the nucleus and help attach cells to one another.
What are microtubules and what are their functions?
They are strands of tubulin that influence cell structure and shape and they are there for motility (organelle movement-cilia/flagella). movement of organelles such as secretory vesicles, of chromosomes during cell division, and of specialized cell projections, such as cilia and flagella.
What are centrioles/centrosomes and what are their functions?
Located near the nucleus, the centrosome consists of a pair of centrioles and the pericentriolar matrix . They are non-membranous.
The pericentriolar matrix of the centrosome contains tubulins that build microtubules in nondividing cells. The pericentriolar matrix of the centrosome forms the mitotic spindle during cell division.
What are cilia and flagellas functions?
A cilium contains a core of microtubules with one pair in the center surrounded by nine clusters of doublet microtubules. They are non-membranous.
Functions of the Cilia and Flagella
- Cilia move fluids along a cell’s surface.
- A flagellum moves an entire cell.
What are microvilli’s function?
Non-membranous organelles. Increase the surface area of the plasma membrane.
What are ribosomes functions?
Non-membranous
- Ribosomes associated with endoplasmic reticulum synthesize proteins destined for insertion in the plasma membrane or secretion from the cell.
- Free ribosomes synthesize proteins used in the cytosol.
What are the functions of the mitochondria?
Membranous organelles that are the site of cell energy metabolism.
- Generate ATP through reactions of aerobic cellular respiration.
- Play an important early role in apoptosis.
What are the nucleus functions?
The nucleus is a membranous organelle that contains most of the cell’s genes, which are located on chromosomes.
Functions of the Nucleus
- Controls cellular structure.
- Directs cellular activities.
- Produces ribosomes in nucleoli.
Where does oxidative ATP Production occur?
- Cytoplasm (in glycolysis)
- Mitochondria (through oxidatitve phosphorylation)
What happens in glycolysis?
The cytosol is the site of many chemical reactions required for a cell’s existence. For example, enzymes in cytosol catalyze glycolysis, a series of 10 chemical reactions that produce two molecules of ATP from one molecule of glucose
What happens in oxidative phosphorylation?
is the process in which ATP is formed as a result of the transfer of electrons from NADH or FADH 2 to O 2 by a series of electron carriers. This process, which takes place in mitochondria, is the major source of ATP in aerobic organisms
What are the functions of endoplasmic reticulum?
The endoplasmic reticulum is a network of membrane-enclosed sacs or tubules that extend throughout the cytoplasm and connect to the nuclear envelope.
Functions of Endoplasmic Reticulum
- Rough ER synthesizes glycoproteins and phospholipids that are transferred into cellular organelles, inserted into the plasma membrane, or secreted during exocytosis.
- Smooth ER synthesizes fatty acids and steroids, such as estrogens and testosterone; inactivates or detoxifies drugs and other potentially harmful substances; removes the phosphate group from glucose-6-phosphate; and stores and releases calcium ions that trigger contraction in muscle cells.
What is the function of the golgi apparatus?
Site of packaging and processing of protein products for secretion.
Functions of the Golgi Complex
- Modifies, sorts, packages, and transports proteins received from the rough ER.
- Forms secretory vesicles that discharge processed proteins via exocytosis into extracellular fluid; forms membrane vesicles that ferry new molecules to the plasma membrane; forms transport vesicles that carry molecules to other organelles, such as lysosomes.
Discuss the process from ribosomes, to rough ER, to golgi, to outside of the plasma membrane.
What do the lysosomes do?
Contain digestive enzymes for recycling old cellular materal, etc.
Lysosomes contain several types of powerful digestive enzymes.
Functions of Lysosomes
- Digest substances that enter a cell via endocytosis and transport final products of digestion into cytosol.
- Carry out autophagy, the digestion of worn-out organelles.
- Implement autolysis, the digestion of an entire cell.
- Accomplish extracellular digestion.
What do peroxisomes do?
Contain enzymes for detoxification of byproducts.
Oxidative phosphorylation vs. Glycolysis
Glycolysis happens in the cytosol and produces:
2ATP
2NADH
PER glucose molecule
as well as 2 pyruvates
Oxydative phosphorylation happens in the mitochondria and produces:
Total: 32 ATP
3 ATP per NADH
2 ATP per FADH2
What are the four nucleotides in DNA?
Thymine
Adenine
Guanine
Cytosine
What are the four nucleotides in RNA?
Adenine
Guanine
Uracil
Cytosine
Define chromosome
- Are nucleic acids (and proteins called histones)
- Are made of DNA
- Condensed
When cell is dividing
Define gene
A sequence (a series of codons) that represents (encodes) a single polypeptide (protein)
Define codon
triplet of 3 bases that represent one of 20 different amino acids
Define transcription
Synthesis of RNA from DNA
Synthesis of a complementary strand of RNA using the base sequence of DNA as a template
Define translation
Synthesis of protein from RNA
Synthesis of protein using the base sequence of RNA as a template
Define exon
a segment of a DNA or RNA molecule containing information coding for a protein or peptide sequence.
Define intron
a segment of a DNA or RNA molecule that does not code for proteins and interrupts the sequence of genes.
Define alternative splicing
Alternative splicing is a regulatory mechanism by which variations in the incorporation of the exons, or coding regions, into mRNA leads to the production of more than one related protein, or isoform
Compare and contrast the characteristics and functional significance of transcription and translation
What are the four phases of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
What is the compostition of nucleic acids?
A sugar, a phosphate group and one of the 4 different nitrogenous bases.
Sugar + base =
nucleoside
Nucleoside + phosphate =
nucleotide
Nucleic acids are sequences of…
nucleotides
What are the pairing in nitrogenous bases and how mych hydrogen bonds do each have?
Adenine with thymine/uracil (2 hydrogen bonds)
Guanine with cytosine (3 hydrogen bonds)
How do you make a new copy of DNA?
To make a copy of a DNA duplex, cells pull the strands apart and match complementary bases to make new strands
What are the two complimentary strands in the double helix of DNA for?
- information encoded in the other strand
- Information concerning protein structure
Define chromatin
Dispersed DNA
-The typical condition of DNA
Main points to remember for transcription
- Occurs in the nucleus
- Produces messenger RNA (mRNA)
- Alternative splicing of exons can produce distince mRNAs from one gene
RNA Polymerase starts at the promoter of DNA. RNA Polymerase goes through and unzips the DNA while making pre-mRNA, the RNA polymerase then re-zips the DNA. Introns are then snipped and exons are spliced together.
Main points to remember for translation
- Occurs in the cytoplasm
- Involves mRNA, rRNA, and tRNA
- Produces proteins
Initiator tRNA (which has anticodon on it) starts at start codon with small subunit underneath attached. Large subunit come and joins with small subunits (this is a functional ribosome) the tRNA fits into the P-site. new anticodon tRNA comes and sits in the site next to the P-site. Amino acids on both tRNAs form peptide bond. tRNA in P-site leaves, mRNA moves so that the second tRNA with the developing peptide chain move into P-site. The cycle continues until mRNA reaches stop codon.
define promoter
DNA sequence ‘upstream’ to the start of a gene to which RNA polymerase binds
Transcription factors
Proteins that bind to the promoter to auhment binding of RNA polymerase
What is prophase
Condensation of DNA in to chromosomes
Metaphase
alignment of chromosomes along a center line or plate (the ‘metaphase plate’)
Anaphase
Separation of ‘sister chromatids’ to daughter cells
Telophase
Formation of two new nuclei
Where in the cell cycle does mitosis occur?
After interphase directly after the G2 phase where the cells grow and proteins synthesize
