Chapter 3/4/6 Flashcards
Explain the relationship between cell function and cell size
-cells composed of organelles that act as machinery
-loss in cellular function can lead to failure of organ system
Cell Theory
-all organisms are made up of cells and are capable of reproduction
-nutrients (glucose and oxygen) enter cell,waste exit, so the amount of surface area affects how much can get in and out of cell
2 light microscopes
compound light: light rays pass THROUGH specimen
stereomicroscope: light rays shine ON surface of specimen
magnification
ratio between size image and object’s size
light/electron rays allows for specimen to be observed a thousand times closer (light) or hundred’s of thousands (electron)
resolution
minimum distance between 2 objects that allows them to be seen as 2 separate objects (great resolving power, greater detail)
compound= oil for increase resolving power
contrast
difference in shading of an object compared to its background
higher contrast= staining cells with dye or electron-dense metals
parts of plasma membrane
Phospholipid bi-layer
glycolipid with carb chain
glycoprotein
phospholipid
cholesterol
peripheral protein
integral protein
functions of plasma membrane
selectively permeable
regulates entrance/exit of substances in/out of cytoplasm to maintain cells
proteins in plasma membrane and their functions
channel proteins: passage of molecules through membrane
carrier proteins: combine w/ substance to help move across membrane
cell recognition protein: help body recognize when it is being invaded by pathogens
receptor proteins: specific molecule bonds and causes proteins to change shape to bring cellular response
enzymatic response: carry metabolic reactions directly, catalyzes reactions
osmosis
diffusion through selectively permeable membrane
diffusion
: movement of molecules from higher to lower concentration, requires NO energy, and leads to equal distribution
key structures of bacterial cell + functions
cell wall
plasma membrane
ribosomes
can be bacillus (rod)
spirillum: rigid spiral with external flagella
spirochete: flexible spiral with internal flagella
coccus: little balls
archaea + bacteria = cell wall, ribosomes, plasma membrane
key structures of bacterial cell + functions
cell wall
plasma membrane
ribosomes
can be bacillus (rod)
spirillum: rigid spiral with external flagella
spirochete: flexible spiral with internal flagella
coccus: little balls
archaea + bacteria = cell wall, ribosomes, plasma membrane
eukaryotes = cell wall (sometimes), PM, nucleus, ribo., organelles
cell wall
compose rigid cell shape- plants & algae
plasma membrane
regulates molecule passage
nucleus
stores genetic info- synthesis of DNA/RNA
nucleoli
ribosomes subunit (in nucleolus)
rough endoplasmic reticulum
modify/transport of proteins for export
smooth endoplasmic reticulum
lipid/carb synthesis in cells and detox of chemicals
golgi apparatus
processing, packaging, distribution of proteins and lipids
lysosomes
intracellular digestion (hydrolytic enzyme, recycle cells)
vacuoles
storage of substances
peroxisomes
smell vesicles that break down toxic materials, break down fatty acids
mitchondria
cellular respiration
chloroplasts
photosynthesis
cytoskeleton
shapes the cell and movement
cilia and flagella
move cell
fimbria: tail attaches bacteria to surface
centriole
cell divisoin
cytoplasm
salt water, organic molecules
structures in cytoskeleton
actin filaments: thin fibers that contain 2 chains of globular actin
role of movement, yields muscle contraction
intermediate filaments: structure roll, rope-like, ketain provides mechanical strength
microtubules: hollow cylinders- radiate from centrosome to help maintain shape and act as tracks
mitochondria & chloroplasts similarities
similar to bacteria in size and structure
bound by double membrane
limited amount of genetic material and divide by splitting
have their own ribo. and protein
RNA suggest prokaryote origin
fluid mosaic model
based on changing location and pattern of protein molecules in phospholipid bilayer
-integral proteins: embedded (molecules channel through them)
-peripheral proteins: on cytoplasmic side (stabilize and shape molecules)
-steroids: regulate fluidity
-cytoskeleton filaments: attached to inside by membrane proteins
signal transduction
- receptor binds to signaling molecule, becomes activated, and initiates transduction pathway
- transduction pathway: series of relay proteins that ends when a protein is activated
- response brought by targeted proteins
-structural: altered shape/movement
-enzyme: altered metabolism/function
-gene-regulatory: altred gene expression
5 functions of membrane proteins
channel proteins: passage of molecules through membrane
carrier proteins: combine w/ substance to help move across membrane
cell recognition protein: help body recognize when it is being invaded by pathogens
receptor proteins: specific molecule bonds and causes proteins to change shape to bring cellular response
enzymatic response: carry metabolic reactions directly, catalyzes reactions
diffusion vs osmosis movement
diffusion: substances move across membrane from HIGH to LOW concentration
-small non charged particles can diffuse thru plasma membrane between phospholipid bilayer
-larger molecules and polar molecules need channel proteins and carrier
osmosis: diffusion of WATER across plasma membrane
-osmotic pressure= dev in system because of osmosis
-solvent= water, moves across mem to HIGHER SOLUTE CONCEN.
aquaporins: channels for moving water
hypertonic: More water INSIDE (crenation(animal shriveling), plasmolysis (plant)
hypotonic: more water OUTSIDE: turgor pressure (plant swelling) hemolysis (red cell swelling) cytolysis (non red)
different membrane transport (energy vs no energy)
ENERGY NOT REQUIRED
Diffusion: towards lower concentration, needs concentration gradient
Facilitated Transport: towards lower concentration, needs channels or carrier and concentration gradient
ENERGY REQUIRED
Active Transport: toward higher concentration, needs carrier and energy
Exocytosis: toward outside, needs vesicle fuse w/ PM
Endocytosis: toward inside, needs vesicle formation, in single cell organisms
-phagocytosis: material taken is LARGE
-pinocytosis: vesicles form around liquid around small particles
-receptor-mediated: receptor takes vitamin, hormone, and binds
DIABETES MELLITUS (how is insulin released in blood)
High blood sugar (glucose) levels over a long period
-Increased urination
-Increased thirst
-Bring blood back to proper Osmotic Pressure
In response to glucose, insulin is released
function of GLUT protein, and how it gets there
Insulin receptors on muscle and liver cells
GLUT4 proteins embedded in vesicle membrane
Vesicle merges with cell membrane
Glucose enters cells by Facilitated diffusion
how insulin affects cells that take up glucose
Rise in blood glucose causes Beta cells in pancreas to release insulin, a protein
Insulin travels to different cells throughout the body to induce them to take up glucose.
forms of energy
kinetic: motion
potential: stored energy
chemical: energy in chemical bonds of molecules such as FOOD
mechanical: form of KE associated with position of motion
2 laws of thermodynamics
- law of conservation of energy: energy cannot be created or destroyed, but it can change from one form to another
-plant cells use solar energy to convert CO2 and H2O to carbs, energy from sun NOT DESTROYED - energy cannot be changed fro one form to another without a loss of usable energy
-heat used in photosynthesis and cellular respiration dissipates into environment
entropy!!
measure of disorder/randomness in system
-2nd law indicates every process in cell increases entropy
-cell remains organized because of constant flow of energy
the different metabolic reactions
metabolism: sum of all chemical reactions
catabolism: breaks down LARGE particles to small
anabolism: smaller molecules are combined to form LARGER molecules
(free energy: amount of energy available so negative means products have less than reactants and positive means products have more than reactants)
exergonic reaction: releases energy
endergonic reaction: requires input of energy
describe the ATP cycle
- ADP + 3 Phosphate
- endergonic reaction: creation of ATP to ADP and phosphate requires input of other energy sources
- adenosine triphosphate is made: ATP is unstable and has high potential energy
- exergonic reaction: hydrolysis of ATP releases stored energy allowing the change in free energy to do work and drive processes
purpose of metabolic pathways and how enzymes regulate them
-metabolic pathway begins with reactant and ends with final product
-each step in MP is catalyzed by an enzyme
-in the 1st reaction, the substrate is catalyzed into the product then THAT product is used as the substrate for the following reaction
activation energy
ENERGY MUST BE ADDED TO CAUSE A REACTION
-addition of enzyme does not change result BUT without an enzyme, the reaction rate will be very slow
enzyme function
enzymes contain active sites where the substrate may bind
-reaction results in degradation of substrate into multiple products (catabolism) or synthesis of a product (anabolism)
-induced fit model: change in active site shape
-factors of speed: substrate concentration, temp/pH, enzyme activation, enzyme inhibtion
function and importance of coenzymes and cofactors
cofactors: nonprotein assistant required by enzyme in order to function INORGANIC IONS (metals Cu, Zn, Fe)
coenzymes: aids in the action of enzyme ORGANIC (NAD+, NADP+, vitamins)
TEMP INCREASE= ENZYME ACTIVITY INCREASE
relationship between metabolic pathways and photosynthesis/cellular respiration
photosynthesis= chloroplasts capture solar energy and convert CO2, H2O into carb (capture sunlight, covert ti chemical ATP) used in hydrogen atoms to reduce CO2
cellular respiration= cells oxidize glucose, energy is gradually stored, convert to ATP
-carbs in chloroplasts become fuel for cellular respiration.
coupled reactions
the energy released by an exergonic reaction is used to drive an endergonic reaction
feedback inhibition
product binds to active site or other site to change the shape of active site
poisons are often enzyme inhibitors
The nucleus
is found in eukaryotes.
stores genetic material.
contains chromatin.
A flagellum is able to bend due to being made of ______________ that can bend by sliding past one another under the influence of the motor protein _____________.
microtubules/dynein
The innermost membrane of the chloroplast is referred to as the
thykaloid
Imagine starting in the innermost space of the chloroplast and moving outward until leaving the chloroplast and entering the cytoplasm. What is the starting points an proper order of things you would move through?
thylakoidspace - thylakoidmembrane - stroma - inner membrane - outer membrane
If you have a 10% sugar solution and a 35% sugar solution, how does the 10% solution compare to the 35% solution
hypotonic
If a cell lacks ATP, which of the following processes would cease to operate immediately
sodium/potassium pump
Receptor-mediated endocytosis involves all of the following EXCEPT
secretion of materials from a cell.
Choose only those that require energy input from the cell whose membrane is directly involved.
Insulin starts out in a vesicle inside a beta cell of the pancreas.When blood sugar level rises the vesicle moves to the cell membrane and fuses with the cell membrane.
Ldlcholesterolreceptorsfill up in a coated pit and the pit is pulled into the cell and made into a vesicle
The cell uses a sodium-potassium pump to create a high concentrationof sodium ions outside the cell.
Glucose levels go up in the bloodstream after a meal. Beta cells of the pancreas detect the elevated glucose levels. This causes them to secrete insulin protein into the bloodstream. How is this secretion accomplished?
Motor proteins drag insulin-containing vesicles to the cell membrane along microtubules
The GLUT protein
MOVES THRU FACILITATEED DIFFUSION
The high energy bond in ATP that is used by cells is found in or between
PHOSPHATE GROUPS
Which is true about energy of activation
the right enzyme lowers activity
If an enzymatic reaction was controlled by feedback inhibition, we would expect it to stop
as soon as a critical level of end product builds up.
In feedback inhibition of a metabolic pathway, where does the inhibitor bind?
. to the enzyme of the first reaction
In which of the following ways is the enzyme inhibitor warfarinused?
rat poison
. anticoagulantmedicine
Which of the following can act a an enzyme cofactor?
iron
B. vitamines
C. NAD+
*D. All of the above.
If you give a child a surgary snack you might notice that they become hyperactive right afterward. Much of the sugar in the blood can be quickly absorbed by the neuronal cells of the brain where the glucose is quickly broken down to create ATP. This is an example of which factor affecting rates of enzymatic reactions?
subtrate concetration
