Test One Flashcards
What is a tissue?
similar cells performing a common function
Neurons/Nervous Tissue (examples & purpose)
Ex: motor neurons, cortical interneurons
Purpose: communication; sending and receiving information
Muscle Cells/Tissue (examples, purpose, voluntary?
Ex: cardiac myocytes, skeletal muscles, smooth muscle
Purpose: contract and generate movement
Atrophy: muscles haven’t contracted in a while and die
Epithelial Cells/Tissue (purpose, where?)
Purpose: exchange and boundaries; lines all body cavities e.g., mouth, nose, ears
Where: makes up most skin; all glands made of this
Epithelial Cells/Tissue (purpose, where?)
Purpose: exchange and boundaries; lines all body cavities e.g., mouth, nose, ears
Where: makes up most skin; all glands are made of this
Connective Tissue (characterized? & examples)
Characterized by: have few cells, lots of extracellular materials (water, salts & proteins), and are diverse
Ex: blood, fat, ligaments, tendons, cartilage & bone
Endocrine Gland
secretes molecules (hormones) into the bloodstream a.k.a. capillaries
Exocrine Glands
uses a DUCT to secrete molecules into a body cavity or exterior body (sweat, saliva)
Homeostasis (what & how)
The body’s ability to maintain a stable (not constant internal environment despite changes in the external environment.
Accomplished through negative feedback and antagonistic effectors
Negative Feedback (what & example)
What: returning conditions to a “set point” and input and output are opposites!
Ex: Sweat when hot. Sweat evaporates and you cool.
Why do you shiver when with a fever?
- Involved in changing the body temp set point (hypothalamus)
- shiver to make fever happen and beat the infection
- you feel cold bc set point had changed to 103
- once infection is defeated, hypothalamus returns set point
- sweat to cool down
Positive Feedback (what & examples)
What: moves conditions AWAY from “set point”/normal conditions. input and output are the same.
Ex:
- Contractions cause oxytocin to be released, causing more contractions. Baby’s head against the cervix activates stretch receptors that signal the hypothalamus to release more oxytocin and cause stronger contractions.
- Scratch a bug bite, which releases histamine, causing it to itch more. Input itching, output itching.
Ionic Bond
between - and + charge
Covalent Bond
two atoms SHARE electrons
Nonpolar Covalent Bond
electrons shared equally, neither will have a charge
Polar Covalent Bond (strong)
electrons go to atom with more protons, shared unequally
Hydrogen Bond
the partial positive charge in a polar covalent bond H2O is attracted to the partial negative charge in the O of H2O
Why don’t water and oil mix?
Oil is made of a lot of nonpolar bonds with no charge. To dissolve in water, it must form hydrogen bonds, but this cannot happen without a charge.
Electronegativity
an atom’s ability to attract and hold electrons; a measure of how + a nucleus is
HCNO*
next to = nonpolar
separated = polar
Monosaccharides (carb)
CHO in a 1:2:1 ratio, ring structure
major purpose: short-term energy
Disaccharides (carb)
2 sugars
Polysaccharides (carb)
hundreds, thousands of monosaccharides
-GLYCOGEN! the energy storage molecule, used for quick energy, metabolized when sugar levels drop
-body does not store glucose well, so when levels are high, glycogen is assembles and stored in muscles and liver
Carb-loading
increasing the amount of glycogen stored in the body prior to a competition
Water Weight/Burning Energy
Body burns through energy blood sugar –> glycogen (w/polar water) –> fat (nonpolar, no water)
Lipids
made of nonpolar hydrocarbon chains and rings, hydrophobic
Saturated Fat
solid @ body temp, no C=C bonds, saturated with hydrogens
Unsaturated Fat
liquid @ body temp, at least one C=C bond, not as many hydrogens
Phospholipids (lipid)
- two fatty acids (nonpolar )& phosphate head (polar) attached to a glycerol backbone
- component of cell membrane for a semi-permeable membrane
Steroid (lipid)
- 4 rings fused
- made from cholesterol, most are sex hormones
- mostly nonpolar
Proteins
made of multiple aa’s whose sequence is determined by transcription and translation
Amino Acids
amino group, carboxyl group, and functional R group
Primary Structure P
order of aa
Secondary Structure P
twists and folds
Tertiary Structure P
3D shape (fx), destroyed when denatured
Quaternary Structure P
more than one chain of aa; braided necklaces
Nucleotides
made of 5-carbon sugar, phosphates, and a nitrogen base
pYrimidine Nitrogen Base
1 carbon ring; cYtosine, thYmine (uracil in RNA)
Purine Nitrogen Base
2 carbon rings; Adenine, Guanine
DNA
instruction for how to build proteins
Chromosome
mix of DNA and proteins
Genes
stretches of information in DNA that code for proteins
Transcription
DNA –> mRNA, occurs in nucleus
Translation
mRNA –> protein, occurs in cytoplasm
Study Transcription outside of this
page 6
mRNA
carries genetic code out of the nucleus
Codons
code for one specific amino acid to be added during translation
AUG
start codon; codes for aa methionine
Stop Codons
UGA, UAG, UAA; stop codons, do not code code for aa
rRNA
forms RNA component, allows for protein assembly
tRNA
allows for protein assembly
1. reads mRNA and brings in the correct aa to build proteins during translation
2. hold anti-codons that recognize and bind to a specific codon in mRNA
study the process of translation
page 6
How can a gene code for more than 1 protein?
mRNA changed after transcription
Proteins made of many polypeptide chains
Protein modification
- Adding lipids to carbohydrate
- Adding a phosphate group
- Cutting into small units
Anabolic Reactions
Production of larger molecules from smaller reactants. Requires energy.
Think A is first, so it uses MORE energy and produces LARGER molecules
Steroid = anabolic that BUILDS muscle
Catabolic Reactions
Breakdown of larger molecules into smaller molecules.
Releases energy
Cats break down their food into smaller pieces to release energy
First Law of Thermodynamics
Energy cannot be created or destroyed, only transformed.
Second Law of Thermodynamics
Usable energy is released as heat with every transformation of energy.
Heat energy is the “cost” of every reaction
Endergonic Reactions
Require an input of energy. Products contain more free energy than reactants
“Energetically Uphill”
Exergonic Reactions
Release energy. Reactants have more free energy than products
“Energetically Downhill”
Exergonic Reactions
Release energy. Reactants have more free energy than products
“Energetically Downhill”
How do ender and exergonic reactions work together?
For an endergonic rxn, there must be an exergonic rxn nearby that releases the correct amount of energy
Activation Energy
Energy required for reactants to engage in rxn; all rxns need this
Can take the form of heat; molecules colliding
Catalysts lower AE by
Increase rate of rxn
Are not changed by rxn (can be reused)
No effect on free energy of R or P
reactants = substrates
Ligand
Anything that binds to a receptor (protein) based on shape
Affinity for bonding to a receptor protein is based on charge
Substrate
reactant that binds to an enzyme
Enzyme Activity
A measurement for the rate at which substrates are converted to product
Regulated by: concentration of enzyme and substrate, Affinity, temp, pH
Covalent Regulation
Certain enzymes in body whose sole function is to activate or inactivate other enzymes
Phosphorylation and De-phosphorylation
Kinase adds a phosphate group and activates enzymes
Phosphatase removes phosphate groups and turns it off
Feedback Inhibition
Too much of anything can be toxic
If “C” accumulates in the cell, it can inhibit enzyme 2 and stop its own production
End Product Inhibition
Some metabolic pathways have more than one end product.
If one builds up, the enzyme can be inhibited to allow other to produce more
study ATP:
the medium of energy exhange and cell resp
How is glycolysis different from every other step in cellular respiration?*
Occurs in cytoplasm
Does not require O2
What is the only step in cellular respiration that does not produce ATP?*
The Linking Step
How is ATP generated?
H+ ions create a gradient and diffuse back into the mitochondrial matrix.
Flow through ATP synthase. Movement activates the enzyme and makes ATP.
Food gets broken down into electrons that get carried by NADH and FADH2.
If we stop eating, no more electrons. Proton gradient reaches equilibrium; ATP no longer made.
Our bodies also burn fats, proteins, and nucleic acids for energy.
What is the purpose of O2? *
To receive electrons at the end of the ETC
How much ATP gets made from glucose?*
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