Biology Flashcards
1
Q
Hierarchic organization
A
- kingdom(largest & most inclusive)
- phylum
- class
- order
- family
- genus
- species (most restrictive)
2
Q
scientific method
A
- observation
- hypothesis- statement or explanation of certain events
- experiment- repeatable procedure of gathering data to support or refute the hypothesis
- conclusion- data and its significance are explained
3
Q
water
A
- 2 H atoms are covalently bonded to 1 O atom
- intermolecular bonding
- high specific heat- amount of heat to raise the temp of 1g of that molecule by 1C
- H bonding of water allows water to resist shifts in temp change
- oceans stabilize the climate
- polarity of water allows it to work as a versatile solvent
4
Q
water; cohesive vs. adhesive
A
- H bonding results in these properties
- cohesive- ability of a molecule to stay bonded or attracted to another moelcule of the same substance
- adhesion- the ability of water to bond to or attract other molecules or substances
5
Q
carbohydrates
A
- long chains or polymers of sugars
- storage, strucutre and energy
- backbone of DNA and RNA
6
Q
fatty acids (lipids)
A
- saturated fats: have no double bonds in hydrocarbon tail, solid, considered detrimental and causes cardiovascular problems
- unsaturated fats: have double bonds, liquid
7
Q
phospholipids (lipids)
A
- contain 2 fatty acids bonded to a phosphate group
- the phosphate group is charged; polar and soluble in water
- the hydrocarbon tail of the fatty acid is non polar and non soluble in water
- helps create a barrier that protects the cell
8
Q
proteins
A
- contribute to cell function
- polymers of 20 molecules called amino acids
- largest of the biological molecules
- enzymes- act to catalyze different reactions or processes
9
Q
nucleic acids
A
- components of the molecules of inheritance
- DNA: code that is necessary for replication (A with T and C with G)
- RNA: used in the transfer of info from DNA to protein level. messenger in most species of the genetic code
10
Q
metabolism
A
- sum of all chemical reactions
- takes place in a series of steps: metabolic pathway
- high energy to low energy
- all reactions catalyzed by enzymes
11
Q
prokaryotic cells
A
-lack a nucleus and do not contain membrane bound organelles
12
Q
eukaryotic cells
A
- have a membrane-enclosed nucleus and a series of membrane-bound organelles that carry out the functions of the cell as directed by the genetic information contained in the nucleus
- more complex
13
Q
nucleus
A
-contains the DNA in organized masses called chromosomes
14
Q
chromosomes
A
-contain all of the genetic information for the regeneration (repair and replication) of the cell, as well as all instructions for the function of the cell
15
Q
ribosomes
A
- organelles that read the RNA produced in the nucleus and translate the genetic instructions to produce proteins
- bound ribosomes are found attached to the ER
- free ribosomes are found in the cytoplasm
16
Q
endoplasmic reticulum
A
- membranous organelle found attached to the nuclear membrane
- rough ER- covered in ribosomes, and responsible for protein synthesis and membrane production
- smooth ER- not covered in ribosomes, functions in detoxification and metabolism of multiple molecules
17
Q
golgi apparatus
A
- packaging, processing and shipping the organelle
- transports proteins from the ER throughout the cell
18
Q
lysosomes
A
- intracellular digestion
- packed with hydrolytic enzymes, the lysosome can hydrolyze proteins, fats, sugars and nucleic acids
- normally contain an acidic environment
19
Q
vacuoles
A
- membrane enclosed structures with various functions
- phagocytosis- uptake of food through the cell membrane creating vacuoles
- plant cells have central vacuoles, functions as storage, waste disposal, protection and hydrolysis
20
Q
mitochondria
A
- produces cells energy
- most eukaryotic cells and is the site of cellular respiration
21
Q
chloroplasts
A
- produces cells energy
- found in plants and is the site of photosynthesis
22
Q
cellular membrane
A
- contributes to protection, communication and the passage of substances into and out of the cell
- consist of bilayer of phospholipids with proteins, cholesterol, and glycoproteins
- phospholipids are amphipathic, this bilayer creates a hydrophobic region between two layers of lipids, making it selectively permeable
23
Q
cellular respiration equation
A
C6H12O6 + 6O2 -> 6CO2 + 6H2O
24
Q
steps of cellular respiration
A
- ATP and NADH are required
1. glycolysis- conversion of glucose to pyruvate - takes place in the cytosol and produces 2 molecules of ATP, 2 molecules of pyruvate and 2 molecules of NADH
2. pyruvate is transported into a mitochondrion and used in CAC - occurs in the matrix of the mitochondria
- for a single consumed glucose molecule, 2 ATP molecules, 6 carbon dioxide and 6 NADH are produced
3. begins with the oxidation of the NADH molecule to produce oxygen and finally produce water, in steps of ETC - for every glucose molecule, 28 to 32 ATP molecules can be produced
- overall ATP production 32-36 ATP molecules for every glucose molecule consumed
25
Photosynthesis
- reverse of cellular respiration
- equation: 6CO2 + 6H2O + Light energy -> C6H12O6 + 6O2
- energy needed to produce glucose
- light reactions and the calvin cycle
26
light reactions: photosynthesis
- convert solar energy to chemical energy
- cell accomplishes the production of ATP by absorbing light and using that energy to split a water molecule and transfer the electron, creating NADPH and producing ATP
- these molecules are then used in the Calvin Cycle to produce sugar
27
Binary fission: asexual reproduction
- involves bacterial cells
- the chromosome binds to the plasma membrane, where it replicates
- then as the cell grows, it pinches in two, producing two identical cells
28
Mitosis: asexual reproduction
- occurs in 5 stages before pinching in two in a process called cytokinesis
- 5 stages: prophase, prometaphase, metaphase, anaphase and telophase
1. prophase- the chromosomes are separate, and each duplicated chromosome has two sister chromatids
2. prometaphase- the nuclear envelope begins to disappear, and the chromosome begin to attach to the spindle that is forming along the axis of the cell
3. metaphase- all chromosomes aligning along the metaphase plate or center of the cell
4. anaphase- begins when cells start to separate, the chromatids are considered separate chromosomes
5. telophase- chromosome gather on either side of the now separating cell
- cytokinesis is separate from phases of mitosis
- the cell pinches in two, forming two separate identical cells
29
sexual reproduction
- 2 cells contribute genetic material, resulting in significantly greater variation
- 2 cells find and fertilize each other randomly, making it virtually impossible for cells to be alike
30
sexual reproduction: meiosis
- 2 stages Meiosis I and II, resulting in 4 daughter cells
- each daughter cell contains half as many chromosomes as the parent
- interphase- when the chromosomes are duplicated and the cell prepares for division
31
mitosis vs. meiosis
- both have the same 4 stages
- biggest difference is in prophase I
- in meiosis during prophase I, nonsister chromatids of homologous chromosomes cross at numerous locations
- small sections of DNA are transferred between these chromosomes resulting in increased genetic variation
- the remaining phases are the same as those in mitosis with the exception of chromosome pairs separate, not the chromosomes themselves
32
genetics
- using garden pea plants, Gregor Mendel discovered the basic principles of genetics
- he was able to determine that the observable traits in peas were passed from one generation to the next
33
genetics: alleles
- in Mendels study, it was found that for every trait expressed in a sexually reproducing organism, there are at least two alternative versions of a gene (allele)
- versions can be dominant or recessive
- if both alleles are the same then they are homozygous
- if both alleles are different they are heterozygous
34
Punnett square
- it is possible to predict the genotype (combination of the alleles) and the phenotype (what traits will be expressed)
35
DNA
-the genetic material of a cell and is the vehicle of inheritance
36
structure of DNA
- 1953, Watson and Crick described DNA as a double helical structure that has 4 nitrogenous bases; A, T, G and C
- each base forms a H bond with another base on the complementary strand
37
replication of DNA
- the strands are separated
- with the help of several enzymes, new complementary strands to each of the two original strands are created
- this produces 2 new double-stranded segments of DNA identical to the original
- when DNA makes a copy of itself, it "unzips" to expose nucleotide bases
- enzyme DNA polymerase unzips it
- after all bases have new pairs, 2 identical DNA molecules will be ready for distribution to the two daughter cells
38
DNA: transcription
- each gene along a strand of DNA is a template for protein synthesis
- begins with transcription
- in this process, an RNA strand, complementary to the original strand of DNA is produced
- the piece of genetic material produced is mRNA
39
DNA: mRNA
- functions as the messenger from the original double helix in the nucleus to the ribosomes in the cytosol or on the rough ER
- here is where translation happens
40
DNA: translation
- ribosomes act as the site of translation
- the mRNA slides through the ribosome
- every group of 3 bases along the stretch of RNA is a codon, and each codes for a specific amino acid
- anitcodon is located on a unit called tRNA
41
DNA: tRNA
- anticodon is located on here
- tRNA carries a specific amino acid
- it binds to the ribosome when its codon is sliding through the ribosome
- a protein is a polymer of amino acids, and multiple tRNA molecules bind in order and released by the ribosome
- each amino acid is bonded together and released by the preceding tRNA molecule, creating a elongated chain of amino acids
- chain ends at a stop codon
- at this point the chain is released into the cytoplasm, and the protein folds onto itself and forms its complete conformation
- as amino acids are brought into the proper sequence, they are joined by peptide bonds and form a long strands of polypeptides
