midterm one info

Question 1

what is neural plasticity?

Answer 1

the ability for our nervous system to be modified after birth

Question 2

what is a synapse?

Answer 2

the junction between neurons, where most remodeling occurs

Question 3

what is the difference between memory and learning?

Answer 3

the storage of memory is an anatomical/physiological event occurring at the synapses. memory is simply the storage of information, while learning is the use of this knowledge/experiences in order to decrease the likelihood of a negative outcome.

Question 4

explain the process of memory storage using the terms sensory memory, short term memory, and long term memory.

Answer 4

sensory memory is memory through stimuli, very short term. Information that is being used in that very moment is stored in the STM for less than 30 seconds. We can hold 7+-2 bits of information in the STM. It can then be released or encoded into LTM. The LTM is permanent storage of information that is not being used ATM and has unlimited capacity. Information from the LTM can be retrieved into the STM when needed.

Question 5

what is chunking and why is it helpful?

Answer 5

chunking is learning sets of related info rather than just one thing at a time

Question 6

what is long term potentiation?

Answer 6

a phenomenon that involves a long-lasting increase in the strength of synaptic connections between neurons. It is considered one of the cellular mechanisms underlying learning and memory in the brain

Question 7

what are the levels of biological organization from biggest to smallest (provide an example)

Answer 7

11. Biosphere (Earth)
12. Ecosystem (Savannah)
13. Community (lions and zebras)
14. Population (pride of lions)
15. Organism (a single lion)
16. Organ/Organ System (heart/digestive system)
17. Tissue (muscle tissue)
18. Cells (blood cell)
19. Organelles (Mitochondria)
20. Molecules (H2O)
21. Atoms (CHON)

Question 8

what is the idea of evolution?

Answer 8

unifying idea of biology-all living organisms are modified descendents of common ancestors

Question 9

What is the unifying idea of biology all organisms are modified descendents of?

Answer 9

common ancestors

Question 10

Define emergent properties.

Answer 10

Properties the result from arrangement and interactions of parts within a system

Question 11

What does the term ‘emergence’ mean in the context of biology?

Answer 11

the whole is more than just the sum of all its parts

Question 12

What is the scientific method?

Answer 12

Method of inquiry, finding natural explanations for natural phenomenon

Question 13

What is a hypothesis and give an example?

Answer 13

a proposed explanation for an observation or a scientific problem that can be tested. It is based on existing knowledge and should be a clear statement expressing a potential answer to a question. An example of a hypothesis could be “A plant given fertilizer will grow taller than a plant not given fertilizer.”

Question 14

What is the difference between a hypothesis and a prediction?

Answer 14

A hypothesis is a proposed explanation for an observation of a scientific problem that can be tested. A prediction is an outcome we would expect to see if a hypothesis is correct.

Question 15

Define the terms ‘theory’ and ‘law’ and provide an example for each.

Answer 15

A theory is a broad explanation with significant support that leads to new hypotheses and accurate predictions, an example would be that the earth revolves around the sun. A law is a statement of what always occurs under certain circumstances, an example would be the conservation of energy.

Question 16

What are electrons and what is their charge?

Answer 16

Electrons are subatomic particles with a negative charge. They can be found in the electron cloud around the nucleus of an atom. They play a crucial role in chemistry, the distribution of electrons in atom electron shells determines how that atom can interact with other atoms.

Question 17

Explain the concept of potential energy.

Answer 17

The energy that an object possesses due to its position relative to other objects or due to its condition or state. It represents the potential for the object to do work.

Question 18

How is potential energy related to electrons and their position in atomic shells?

Answer 18

Potential energy also refers to the energy that electrons have based on their positions in relation to the nucleus of an atom. The further an electron is from the nucleus, the higher its potential energy.

Question 19

What factors affect an atom’s number of bonds?

Answer 19

Number of valence electrons affects the number of bonds

Question 20

Define a molecule and provide an example with its chemical formula.

Answer 20

A compound of 2 or more atoms held together by chemical bonds. A molecule can be described by its chemical formula, which provides the type of atom and the number of each. A water molecule has the chemical formula (H2O)

Question 21

What is electronegativity and how does it influence the formation of chemical bonds?

Answer 21

A measure of an atom’s ability to attract electrons in a chemical bond toward itself. Atoms with high electronegativity tend to attract electrons more strongly than atoms with low electronegativity

Question 22

Differentiate between non-polar covalent bonds, polar covalent bonds, and ionic bonds.

Answer 22

Nonpolar: same/similar electronegativity, electrons are shared equally
Polar: unequal electronegativity, electrons shared unequally resulting in partial charges
Ionic: highly unequal electronegativity, 1 atom loses an electron while another gains an electron which results in an ion (charged atom). Formed between attraction between an anion (-) and cation (+).

Question 23

What are salts and how are they formed?

Answer 23

A compound formed by ionic bonds and create a crystal lattice structure

Question 24

Describe van der Waals forces and hydrogen bonds.

Answer 24

Van der wall forces are relatively short lived/weak interactions due to electrons position and motion. Areas with partial negative/positive interact. They are strong in large numbers. Hydrogen bonds are a type of van der waals force, partial positive and negative charges result when a hydrogen binds to an electronegative atom. The positive charge of a hydrogen tends to associate with a negatively charged atom, like nitrogen.

Question 25

Why is water considered a polar molecule?

Answer 25

There are polar covalent bonds

Question 26

Explain the terms ‘cohesion’ and ‘adhesion’ in the context of water molecules.

Answer 26

Cohesion is the property of water molecules to stick together. An example would be surface tension. Adhesion describes water molecules’ property to be attracted to other things. An example is water transportation in plants.

Question 27

explain the property of water to moderate temperature

Answer 27

water has a high specific heat and it is hard to change its state. The stable environment allows water to not overheat which is important to aquatic life. The high specific heat can be explained by how hard the hydrogen bonds are to break due to their large amounts.

Question 28

Why does water expand upon freezing?

Answer 28

The water molecules are arranged with more space between them compared to the liquid state. There are more air pockets between the hydrogen bonds which makes the solid frozen state less dense than the liquid state.

Question 29

Define ‘hydrophilic’ and ‘hydrophobic’. Provide an example for each.

Answer 29

Hydrophilic describes substances with affinity for water, these are typically polar molecules with regions of positive and negative sides. They are able to dissolve in water
(salts and ions). Hydrophobic substances have no affinity for water. They are non-polar and can not dissolve in water (oil).

Question 30

what is the significance of carbon in biological molecules?

Answer 30

carbon is the foundation of organic compounds, forming complex structures due to its ability to make four covalent bonds. It plays a crucial role in the chemistry of life.

Question 31

how does the geometry of carbon molecules affect their function?

Answer 31

the geometry of carbon molecules influences their function, and the carbons ability to form four covalent bonds contributes to the complexity of organic compounds.

Question 32

what is a hydrocarbon and provide an example stating its characteristics

Answer 32

Hydrocarbons are organic molecules that contain only C and H. Methane (CH4) is a hydrocarbon. It is a non-polar, uncharged, hydrophobic, and can contain functional groups by replacing one or more hydrogen atoms.

Question 33

explain the role of functional groups in molecular function

Answer 33

functional groups are essential for molecular function as they replace hydrogen atoms and can significantly alter the properties of molecules, impacting their role in biological processes.

Question 34

list all of the polar/hydrophilic functional groups and state whether they are acidic, basic, or neutral

Answer 34

Hydroxyl (-OH) Neutral
Carbonyl (-C=O) Neutral
Sulfydryl (-SH) Neutral
Carboxyl (-COOH) Acidic (-)
Phosphate (-PO4) Acidic (-)
Amino (-NH2) Basic (+)

Question 35

list all of the nonpolar/hydrophobic functional groups and state whether they are acidic, basic, or neutral

Answer 35

methyl (-CH3) Neutral

Question 36

what are macromolecules?

Answer 36

large, complex molecules composed of small subunits called monomers. these molecules play a fundamental role in the structure and function of living organisms.

Question 37

compare and contrast hydrolysis and dehydration synthesis?

Answer 37

dehydration synthesis is the process of removing a water molecule in order to form a bond while hydrolysis is the process of adding an water molecule in order to break a bond.

Question 38

what are carbohydrates?

Answer 38

organic compounds composed of carbon (C), hydrogen (H), and oxygen (O) atoms. their main functions include fuel and energy storage. they can be classified into three main groups: monosaccharides, disaccharides, and polysaccharides.

Question 39

what are monosaccharides?

Answer 39

the simplest form of carbohydrates, consisting of a single molecule
example: glucose, fructose, and galactose

Question 40

what are disaccharides?

Answer 40

polymer formed by the combination of two monosaccharide molecules through a dehydration synthesis reaction. the covalent bond btwn the molecules is called glycoside linkage.
example: sucrose

Question 41

what are polysaccharides

Answer 41

polymer of complex carbohydrates made up of long chains of monosaccharides
functions: storage (starch & glycogen) and structure (cellulose & chitin). the function is determined by the type of monomer and position of glycosidic linkage.

Question 42

what are lipids?

Answer 42

diverse group of organic molecules that share a common feature of being hydrophobic, meaning they are not soluble in water and only dissolves in non polar solvents. there are three important lipid forms, fats, phospholipids, and steroids.

Question 43

what are fats?

Answer 43

triglycerides, nonpolar and hydrophobic, composed of glycerol and three fatty acid molecules. fats serve as long term storage and can come in two forms, saturated and unsaturated

Question 44

compare and contrast saturated and unsaturated fats

Answer 44

in saturated fats, all carbon atoms in the hydrocarbon chain are linked by single bonds and the molecule is saturated with hydrogen atoms. they tend to be solid at room temperature and are commonly found in animal products while unsaturated fats contain one more more double bonds in the hydrocarbon chain. unsaturated fats can be categorized into monounsaturated (one double bond) or polyunsaturated (2+ double bonds). unsaturated fats are often liquid at room temperature and found in plant oils. the bonds are called ester linkages.

Question 45

what are phospholipids

Answer 45

made up of phosphate, two fatty acids, and one glycerol. used in the cell membrain because they are amphipathic (hydrophillic and hydrophobic regions)
fatty acid tails: hydrophobic
phosphate head: hydrophilic

Question 46

what are steroids?

Answer 46

three 6C rings and one 5C ring, they differin in functional groups. examples include cholesterol and sex hormones.

Question 47

what are proteins?

Answer 47

play a crucial role in the structure and function of living organisms, they basically do everything but heredity. they are essential components of cells and are involved in a wide range of biological processes. proteins are made up of amino acids (monomer), there are 20 types of amino acids that can be combined to form a protein. proteins have multiple structures: polypeptide, secondary, tertiary, and quaternary.

Question 48

what is the classification of amino acids?

Answer 48

they all have the same basic structure, central carbon, hydrogen atom, carboxyl group (acidic), and amino group (basic), but differ with side chains, the r group. the r group can be hydrophobic, hydrophilic, or charged (acidic/basic).

Question 49

what is a polypeptide?

Answer 49

many amino acids joined together via peptide bonds between carboxyl and amino groups in a linear sequence. not a protein yet.

Question 50

what is the secondary structure of a protein?

Answer 50

local folding of the polypeptide chain into alpha helix or beta pleated sheets. the folding is stabilized by hydrogen bonds.

Question 51

what is tertiary structure of a protein?

Answer 51

folds into a 3d shape, resulting from interactions between the amino acid side chains (r groups). there are multiple types of bonds: hydrogen bonds, polar, nonpolar, ionic, ect.

Question 52

what is quaternary structure of a protein?

Answer 52

the arrangement of multiple polypeptide chains in a protein complex. there are all types of bonds, no more folding, just more polypeptide chains are added.

Question 53

what are the effects of protein unfolding?

Answer 53

denaturation, which is the loss of proteins native structure. if the structure is lost, so is the function. this can be caused by pH levels, salt concentration, and high temperatures

Question 54

nucleic acids

Answer 54

DNA & RNA, sugar backbone, phosphates and sugars

Question 55

what is abiogenesis?

Answer 55

also known as spontaneous generation, it is the hypothetical process by which living organisms can arise from non-living matter. suggests the transition from nonliving to living entities occurred some point in earth history.

Question 56

what is the process of abiogenesis?

Answer 56

requirements: need low O2, a source of energy to stick the monomers together, chemical building blocks, and time
1. synthesis of monomers: under early earth conditions, simple organic molecules such as amino acids and nucleotides are formed through abiotic synthesis, this could involve reactions in the atmosphere or on mineral surfaces.
2. monomer forms macromolecule: simple organic molecules undergo polymerization to form larger, more complex macromolecules. this includes the formation of proteins, nucleic acids, and carbohydrates. these macromolecules are the building blocks of life.
3. formation of protocells: lipid molecules spontaneously organize into membrane like structures called protocells. these protocells encapsulate organic molecules, creating an environment for chemical reactions to occur within a semi isolated space
4. appearance of self-replication: within protocells, or through other processes, self replicating molecules, such as RNA, emerge. These molecules have the ability to store genetic information and catalyze their own replication.

Question 57

what is the RNA world hypothesis?

Answer 57

the first cells used RNA to store and copy genetic info. DNA and proteins were incorporated later.

Question 58

what were the first cells?

Answer 58

prokaryotes, which were anaerobic, heterotrophic, and obtained organic molecules from the environment. autotrophic cells were another type of prokaryotic cells that were capable of using energy from sunlight to synthesize their own food

Question 59

what was the oxygen apocalypse and what came out of it?

Answer 59

2.5 BYA, rise in atmospheric O2 due to organic photosynthesis, this killed off most organisms and caused aerobes to take over. aerobes were capable of aerobic respiration and became dominant, benefiting from the higher ATP yield

Question 60

what is the endosymbiotic theory?

Answer 60

how eukaryotic cells could have evolved from prokaryotic cells

Question 61

what is endosymbiosis

Answer 61

endosymbiosis is the process that describes the establishment of a symbiotic relationship between a host cell and engulfed bacteria or other small cells. the most widley accepeted sequence is associated with the evolution of eukaryotic cells, particularly the origin of mitochondira and chloroplast

Question 62

what is the sequence of endosymbiosis?

Answer 62

it starts with the engulfment of bacteria, the host cell engulfs free living aerobic bacterium through phagocytosis, this bacterium avoids digestion and becomes endosymbiont within the host cell. the host cell and the bacterium establish a mutualistic relationship, the bacterium enhances ATP production through aerobic respiration. overtime the bacterium evolves into what is known as the mitochondrion. the host cell and mitochondrion become mutually dependent. in some lineages a photosynthetic bacterium was engulfed and that bacterium evolves into a chloroplast. the host cell, now containing a mitochondria and potentially chloroplasts, evolves into a eukaryotic cell.

Question 63

what is a cell?

Answer 63

the smallest unit that carries out all activities associated with life, can do everything or be specializes, all cells share common features and evolutionary history

Question 64

in what ways do prokaryotes and eukaryotes differ?

Answer 64

prokaryotic cells are tiny and contain a nucleoid (unbound circular DNA) rather than a nucleous. there are no organelles, no receptors, and they divide via binary fission. prokaryotes have complex cell wall and a cytoskeleton. there are small ribosomes. examples include archaea & bacteria. eukaryotes are large and have a membrane bound nucleus (which contains linear dna) and nucleolus (makes ribosomes). organelles and receptors are present. prokaryotes divide via mitosis. plant cells have a simple cell wall but there are no cytoskeleton. the ribosomes are large and examples include animals and plants.

Question 65

how are prokaryotes and eukaryotes similar?

Answer 65

both have a flagella, plasma membrane, cell division, cytoplasm, ribosomes, and chromosomes

Question 66

what is the nucleus in eukaryotic cells?

Answer 66

the nucleus contains most DNA, a nuclear envelope (double membrane), and has a nucleolus, which is the region of ribosome production within a nucleus

Question 67

what are the mitochondria and chloroplast in eukaryotic cells?

Answer 67

they are organelles acquired via endosymbiosis. the mitochondria (aerobic) is where cellular respiration takes place and is present in all eukaryotic lineages. chloroplast is where photosynthesis takes place and can be found in photosynthetic lineages (mostly plants and algae)

Question 68

what is the evidence for endosymbiosis?

Answer 68

double membranes; similar size, enzymes, ribosomes to bacteria; DNA sequences very similar to living bacteria; divide via binary fission

Question 69

what are ribosomes?

Answer 69

the structures responsible for protein synthesis. they are not membrane bound and not considered organelles. they are made of protein and RNA and can be found in the cytoplasm and/or associated with the endoplasmic reticulum

Question 70

what is the endomembrane system?

Answer 70

it is the internal membrane system, divides the cell into compartments (membrane bound organelles)

Question 71

what is the endplasmic reticulum

Answer 71

an internal membrane complex that is connected to outermembrane of nuclear envelope.
rough ER: protein synthesis
smooth ER: lipid synthesis

Question 72

what is the golgi apparatus?

Answer 72

many membranes, modify and transport proteins

Question 73

what are vacuoles?

Answer 73

large vesicles derived from the endomembrane system. have many functions: food vacuoles, contractile vacuoles, storage in plants cells

Question 74

what are lysosomes?

Answer 74

compartments contraining hydrolytic and digestive enzymes
primer lysosome: made in RER, processed in golgi, inactive
secondary lysosome: fuses with vacuole, active

Question 75

what are the components of a membrane?

Answer 75

phospholipid bilayer, carbohydrates, cholesterol, and membrane proteins

Question 76

what is the phospholipid bilayer? describe its structure and function.

Answer 76

phospholipids are the principle component, they are made up of a phosphate group (hydrophilic) and a glycerol + 2 fatty acids (hydrophobic). they form bilayers, which are hydrophobic interactions that shield the trails from aqueous environment. functional component of cell membranes, providing a barrier, regulating the passage of molecules, facilitating cell signaling, maintaining compartmentalization, and serving as a platform for various cellular activities

Question 77

what are carbohydrates in the context of membrane structure? describe their structure and function.

Answer 77

different polysaccharides attached to a protein to create a glycoprotein or a lipid to form a glycolipid. they are used for cell identification.

Question 78

what are proteins in the context of membrane structure? describe their structure and function

Answer 78

membrane proteins can be peripheral, bound to the surface and hydrophilic OR integral, deeply inserted, transmembrane, amphipathic. proteins determine most main function of the membrane such as transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, attachment to exoskeleton and extracellular matrix

Question 79

explain what the fluid mosaic model is

Answer 79

describes the cell membrane. the phospholipids move laterally within one layer, they have fluidity. if the layer is pushed it will move, if its poked hard enough it will break and regroup. factors that can affect the fluidity include temperature, fatty acid chain length, degree of fatty acid saturation, and the cholesterol. the mosaic aspect describes how there are different molecules and components present in the cell membrane.

Question 80

what are the type of passive transports? compare and contrast them and give an example of each.

Answer 80

no ATP is required and they all move with the gradient. there are three types: simple diffusion, osmosis, and facilitated diffusion.

Question 81

what is simple diffusion?

Answer 81

tendency to move substances to fill up available space. the less space inside the cell, some substances will diffuse across the membrane to occupy more space (equalize). small gases like CO2 and N2, small nonpolar molecules, and small uncharged polar molecules like water

Question 82

what is osmosis?

Answer 82

a type of passive transport/diffusion of H2O across a selectively permeable membrane from a region of high H2O to a region of lower H2O. H2O moves across a membrane, solutes do not.

Question 83

compare and contrast hypotonic and hypertonic solutions

Answer 83

hypERtonic solutions have higher solute outside compared to inside (water moves out) while hyPOtonic have lower solute inside compared to the outside (water moves in)

Question 84

what is facilitated diffusion?

Answer 84

assistance from transmembrane protein, no metabolic energy required.
channel proteins: used to funnel ions, the protein does not change shape, allows solutes to pass through
carrier proteins: bind to specific substances, the protein changes shape and carries the substance through

Question 85

what are the types of active transport?

Answer 85

uses metabolic energy ATP) and moves against the concentration gradient. there are two types of active transport, bulk transport and pumps/carries (transport proteins)

Question 86

what are pumps and carriers?

Answer 86

integral proteins that change shape and move substances through a membrane. an example would be the sodium potassium pump which is in all animal cells. 3NA+ out and 2K+ in.

Question 87

what is bulk transport?

Answer 87

transporting large molecules, always requires the input of energy from the cell. Two types of bulk transport, exocytosis and endocytosis.

Question 88

compare and contrast the types of bulk transport

Answer 88

exocytosis: a vesicle fuses with the plasma membrane and the contents are released from the cell. it is the primary mechanism for growth of the plasma membrane.
endocytosis: three types that are all used to take material into the cell by forming vesicles from the plasma membrane.
1. phagocytosis: cell ingests large solid particles and creates a food vacuole and fuses with a lysosome to digest the food particle
2. pinocytosis: cell surrounds fluid/dissolved material particles and pinches off part of its membrane to enclose the particles within its vesicles, the contents are slowly transferred to cytoplasm
3. receptor mediated: receptor proteins in the plasma membrane bind to specific macromolecules. they form coated pits and fold inward to form a vesicle. the receptor and vesicle split and the vesicle heads to lysosome while the receptor returns to the plasma membrane

Question 89

what is metabolism?