Unit 2 Study Guide
Chapter 5: Cells
1) What is the definition of a cell?
Smallest unit of structure and function in organisms
2) What are the early contributors to the microscope and their contributions?
Galileo made the first crude microscope in early 1600s
Robert Hooke used a similar device in mid 1600s, slice of cork and saw called “cellulae”
meaning small rooms
Leeuwenhoek looked at microscopic sperm cells and drop of water
3) What is the cell theory?
Every organism is composed of one or more cells
The cell is the smallest unit having all properties of life
“life arises from growth of division of single cells”
4) What is the difference between prokaryotic and eukaryotic?
Prokaryotic: free floating bacteria
Eukaryotic:
oAnimal cells- have nucleus, cell membrane, cytoplasm, and NO cell wall
oAnimal- has plasma or cell membrane, cytoskeleton, centrioles, mitochondria,
nucleus, endoplasmic reticulum, ribosomes, Golgi body, vesicles
What is Cytoskeleton?
oMicrotubules- allow movement by acting like “train tracks” along which
organelles can move
oMicrofilaments- having roles in separating the cell during the cell division,
movement, and cell shape
oIntermediate filaments- give shape and support to the cell by reinforcing the cell
membrane and nuclear envelope
What is Mitochondria Function?
o“powerhouse of the cell”
oReleases the energy stored in bonds of glucose molecules, these are stored in
the ATP molecules (respiration)
oThe more energy a cell needs the greater the number of mitochondria that cell
will have
What are the components of nucleus?
oNuclear envelope- double-double lipid by-layer with regulated “pores”
oNucleus- region of nucleus where ribosomes are assembled
oChromatin- DNA+ associated proteins
Endoplasmic Reticulum (ER)
oStructure: a system of channels (rough ER) and pipelike region (smooth ER) of
membrane sacs that are connected to the nuclear membrane
oFunction: modifies new polypeptide chains; synthesizes lipids
What is the Golgi Body?
oA series of flattened, membrane-bound sacs
oMembranes bulge out and break away into the cytoplasm
What are the Vesicles?
oStructure: small, membranous sacs that move through the cytoplasm or stay
suspended it
oFormed by pinching off of the Golgi body
oFunction:
Lysosomes- have digestive enzymes and serve to digest biomolecules or
parts of the cell or bacteria
Peroxisomes- break down the fatty acids and amino acids, degrade
alcohol in the liver and kidney
What are animal cells functions?
oPlant cells- have nucleus, cell membrane, cytoplasm, Cell Wall (with some
chloroplast and central vacuole)
5) What is plant cell functions?
oPlant cell features- plasma membrane, nucleus, ribosomes, endoplasmic
reticulum, Golgi body, vesicles, centrioles, mitochondria, cytoskeleton, cell wall,
central vacuole, and chloroplast
oPlant cell wall- two layers of cell wall
primary cell wall-outer, cellulose only and secondary cell wall- inner,
cellulose and lignin
oCell membrane is the innermost layer
6) What are cells common features?
All have cell membrane, cytoplasm, nuclear region
oCell membrane (plasma membrane)- holds cells to separate, this allows materials
to enter and exit the cell
oCytoplasm- semi fluid matrix that’s between the nucleus and cell membrane, has
organelles
oNucleus- membrane bound organelle, this contains the DNA or region inside cell
holding DNA
oWhat are organelles
7) What is the Plasma Membrane Fluid?
Not a solid, but continuously moving fluids
Composed of three classes of molecules
oLipid- phospholipids and sterols
oProtein- transporters, receptors, adhesion, and proteins for self-recognition
oCarbohydrates- sometimes attached to protein and lipids on the outside, a
protection, cell recognition, and glue
8) Plasma Membrane: Protein Component Fluid Mosaic Model
Structural proteins- strengthen the lipid bilayer
oForm attachments to other cells and structures
Transport proteins- carry ions or molecules through the membrane
oSome are regulated by the cells
Communication proteins
o receptors: receives external signals like hormones
oIdentification: part of immune system “self-recognition” mechanism
9) Chloroplasts and their functions
Photosynthesis takes place in chloroplast
Process by which the energy from the sun is transferred to the bonds of glucose
molecules
Inside each chloroplast are what looks like stacks of green pancakes, these are called
thylakoid, the stack of thylakoid is stoma
Chapter 6: Tissues, Organs, Organ System
1. Human Organ System- Movement and Support
Integument System- dermis and epidermis
Muscular system- striated muscle and connective tissue
Skeletal system- bone and cartilage
2. Human Organ system- signaling and control
Nervous system- neurons and neuroglia
Endocrine system- pituitary gland, adrenal gland, gonads, pancreas, thyroid, and thymus
3. Human organ systems- Food processing
Digestive system- digestive tract, pancreas, liver
Urinary system- kidneys and urinary bladder
4. Human organ system- Transportation and respiration
Nose, trachea, lungs
Circulatory- heart, blood vessels, blood
5. Human organ system- procreation
Reproductive (Male)- penis and testes
Female- ovaries, fallopian tubes, and uterus, vagina
6. Tissue Types
Epithelium, Connective, Specialized Connective, Muscle, Nervous
Epithelial- tissue forms the protective outer layer or linings of organs, glands and ducts
oSingle cells of this tissue fit tightly together in single or multilayered
arrangements; cell junctions from seal to prevent leaks
oLocation- epidermis and linings of tissues, organs and glands
oStratified squamous- epidermis
oSimple squamous- lining of blood vessels
oCuboidal- lining of ducts and glands
oColumnar- linings of intestines, glands and ducts
oStructure-
Connective Tissue- supports and connects organs and provides cohesion and attaches
muscle to bone and so maintains the form of the body
oComposition- fibers embedded in non-cellular material-collagen (protein) elastin
and proteoglycans
oBoth synthesized by a cell called fibroblasts
oFibers along with other chemicals make some of the tissues loose and stretchy
and others tough and resilient
oLocation- capsules surrounding organs, tendons and ligaments, ends of long
bones, beneath dermis
Loose- beneath dermis
Dense, irregular- capsule surrounding organs
Dense, regular- tendons and ligaments
Cartilage- ends of long bone, nose, trachea
Specialized Connective Tissue
oBone- cartilage which has been strengthened by addition of calcium salts
oAdipose- large yellow white cells which store fats, found skin, around heart and
in abdominal cavity
oBlood- is derived from cells of connective tissue, blood cells originate in bone
marrow, RBC’s carry O2 and Wbc’s provide the immune response of body
Muscle Tissue- provides movement and support
oContain cytoskeletal protein fibers called actin arranged with myosin which pull
on each other to shorten the length of cells
oLocation- heart, organs, attached to the skeleton
oMuscle fiber=muscle cell
oMyofibril= contractile units within the cell
Made up of actin and myosin protein molecules
oLocation-
Skeletal muscle- used to move bones of body relative to each other
Smooth muscle- involuntary movements such as gut concentration,
squeezing glands for secretion, emptying bladder
Cardiac muscle- found only in heart, cells are interconnected by gap
junctions so that contractions are together
Nervous Tissue- carries signals to and from the brain using electrical impulses
oComposition- neurons and neuroglia
oLocation- throughout the body
oNeurons- have cellular extensions that can extend a few millimeters to several
feet
Motor- carry signals to muscles
Sensory- receive signals from the various sensors
oNeuroglia- support function; form protective coatings of nerve fibers, remove
neurotransmitters after nerves fire, provide the paths along which nerves grow
7. What is homeostasis and what it controls?
The maintenance of physical and chemical aspects of the body’s internal environment
within a range favorable for cellular activities, is achieved
oConstant temp, hydration, blood sugar, pH, etc.
Receptors- detect sight, sound, taste, hot, cold, motion
Integrator- usually the brain, receives the information and determines how best to
respond
Effector- muscles, sweat glands, digestive system
Chapter 10: Nervous System
1. What are two systems that nervous system is divided into?
Central Nervous system- brain and spinal cord
Central nervous system (BRAIN):
oConscious control- cerebral cortex (cerebrum)
oCenters of unconscious control- thalamus, hypothalamus, pituitary, medulla
oblongate, cerebellum, midbrain
oThalamus- relays sensory info to the cerebral cortex
oHypothalamus- major control center for homeostasis, regulates hunger, thirst,
sex drive, etc.
oPituitary- master endocrine organ
oMidbrain- visual and balance reflexes
oMedulla Oblongata- controls breathing and heart
oCerebellum- center for muscular coordination
What are lobes of cerebral cortex? - frontal lobe, parietal, occipital, temporal
oFrontal- motor skills, long-term memory, judgement of right/wrong, olfactory
bulb: smell
oParietal- sensory inputs from body; hands, feet, limbs are mapped to 2D regions
of this lobe
oOccipital- sensory input from eyes
oTemporal- sensory input from ears and smell
Peripheral Nervous system
oautonomic nerves: unconscious controls of internal organs and structures
sympathetic nerves- “fight or flight”
increases heart rate, blood flow, and awareness
decreases digestive activity
response to danger or sexual activity
parasympathetic
decreases heart rate, blood flow, and awareness
restores resting state
stimulates basic functions (digestion)
Both are in competition
oSomatic nerves: sensation and movement of head, trunk and limbs
Sensory and motor
Deliver info from pain, temp and touch sensors in skin
Provides info from muscle and tendons regarding tension on muscles
Provide positional info from sensors in joints
Motor nerves- deliver commands to skeletal muscles to cause
muscle contraction
Muscle reflexes- direct response to sensory inputs that bypass the
brain
2. What is the Nerve Function? - dendrites, cell body, and axons
Dendrites- receive signals from other nerves
Axons- transmit signals from cell body to the synapse
Synapse- releases neurotransmitter
Nerve Signaling
oNerve polarization- resting
Na+K pumps Na+ out of cell and K + into cell
K+ ports allow some K+ to leak back out of the cell
Inside becomes negative outside becomes positive
oNerve depolarization- action potential
Signals from dendrites cause depolarization of cell body
Voltage gated na+ ports open and further depolarize the cell
This triggers Na+ ports along the membrane to open
oSignal propagation- continuation of action potential down the axon
Depolarization spreads along the axon like a wave
Behind wave is voltage gated k channels open and allow k to flow out of
cell causing the Na+ channels to close
oNeurotransmitter release- signal passing to next neuron
Arrival of action potential causes fusion of secretory vesicles with
membrane and neurotransmitter release
oPost-synaptic signal
Release of neurotransmitter results in opening of neurotransmitter-
gated channels on postsynaptic cell
Muscles can contract, neurons depolarize (signal continues)
Chapter 10: Digestive System
1) Digestive system in animals
Incomplete digestive system
oOne-way saclike digestive cavity
oSame opening in and out (ex. Flatworms, cnidarians or jellyfish)
Complete digestive system
oA tube with mouth at one end and anus at the other
Digestive specialization
oBirds- digestive system is often subdivided into function regions. This reflects
feeding behavior (seed-eaters)
oFour chambered stomach with bacterial symbionts that help breakdown
cellulose
2) Human Digestive
Mouth (oral cavity)
oTeeth, glands, and tongue
oLiquification- mastication (chewing)
oTeeth grind and tear food (physical digestion
oTongue- positions food for swallowing (roll food into a ball or “bolus”
oLiquification and Molecular Breakdown- salivary glands secrete “saliva”
Amylase enzyme- begins the breakdown of polysaccharides- chemical
breakdown
Mucus- moistens the food
Buffers- hydrogen carbonate (HCO3)
Pharynx (throat)
Esophagus
Liver
Gall bladder
Pancreas
Gut
oStomach, small intestine, large intestine, rectum, and anus
Stomach
J-shaped organ lies below the diagram; sphincters at both ends
Outer serosa- (epithelium and connective tissue)
Covers smooth muscle layers
Inner layer of glandular epithelium- mucosa
Mucus cells secrete mucous; gastric pits contain exocrine cells that secrete gastric fluid
What is in the stomach- (liquification) gastric contractions- stomach churn to continue
breaking food down into small particles and solutes, physical digestion
Repeated contraction and relaxation breaks up the food
During contractions chyme is gradually forced into duodenum through a sphincter into
the small intestine
Molecular breakdown
oGastric fluid (stomach fluid)- hydrochloric acid (HCL), mucus, pepsinogens,
gastrin, (stimulates secretion of gastric fluid)
oChemical breakdown of proteins
oThis results in: chyme=liquified food
Nutrient Absorption- alcohols are absorbed
3) What are the steps of Digestion?
Liquification, Molecular break-down, Nutrient Absorption, Water Resorption, Water
Disposal
4) What molecule moves from the small intestine into the lymphatic system
Fats leave epithelial cells by exocytosis and enter the lymphatic capillaries
5) Small Intestine
Duodenum- top part where chemical digestion takes place (10 in)
oDisaccharidase breaks down disaccharides to monosaccharides
oThe nucleus breaks down nucleotides into base and ribose
oPancreas- proteases break down of proteins
Lipase breaks lipids
Nucleases break down RNA
oLiver- secretes bile with aids in fat digestion by separating fat clumps
(emulsification)
Jejunum- twisty part amino acids and sugars are absorbed in the blood stream (8 feet)
Ileum- last 12 feet
It is 20 feet long with a 1 in diameter
Has a large surface area for majority of absorption
6) Know the muscle motion that moves food and waste along the esophagus and small and
large intestines
Peristalsis- food movement down the esophagus is accomplished through contractions
of the muscular wall
7) What are the roles of the urinary system?
Renal System- removes metabolic wastes from blood
oUrea- break down of amino acids
oUric acid: break sown of nucleotides
oOther break down products (toxins and drugs)
oRegulate water content of blood
oRegulate mineral and salt content of blood
Urinary System- kidneys, ureters, bladder, and urethra
oKidneys- filter the blood and control water and salt concentration in blood
Renal capsule- thin, transparent layer of fibrous connective tissue
Renal cortex and medulla- continuous band of tissue
They extend through each cortex contains mostly Bowman’s
capsule and glomerular capillaries
Medulla contains mostly loop of Henle and peritubular capillaries
oUreters- collects and carries urinary from kidney to urinary bladder
oBladder- stores urine (water, salts, nitrogenous wastes)
oUrethra- canal that empties out the bladder; excretes the urine
What is Urine?
oWater, salts, nitrogenous wastes
Nephron- function unit of the kidney. It consists of a renal tubule and associated
capillaries
step 1) filtration of solutes- all solutes except proteins pass into bowman’s capsule,
results of “leaky” capillaries and driven by blood pressure
step 2) solute reabsorptions- proximal tubules reabsorb needed solutes
oglucose, amino acids, bicarbonate, electrolytes: Na+, Cl-
ouse specific transport proteins in tubule cells
step 3) urine concentration- na+ channels in loop of henle and distal tubule transfer na+
out of urine; outside of tubule becomes “salty”; osmotic pressure pulls water out of
proximal and distal tubule and collecting ducts
High blood pressure damages the filtering of capillaries
