Biology Flashcards
Biology hierarchic organizational system in order from most inclusive to most restrictive category:
Kingdom Phylum Class Order Family Genus Species
Steps of the scientific method:
- Observation 2. Hypothesis 3. Experiment 4. Conclusion
Observation:
New observations are made/previous data are studied
Hypothesis:
Statement or explanation of certain events or happenings
Experiment:
Repeatable procedure of gathering data to support or refute the hypothesis
Conclusion:
Data is explained
Most significant aspect of water:
The polarity of its bonds that allow for hydrogen bonding between molecules
Specific heat:
Amount of heat necessary to raise the temperature of 1 gram of that molecule by 1 degree Celsius
Why is polarity the most important characteristic of water?
The results of the polarity are hydrogen bonding, a high specific heat value, versatile solvent, strong adhesive and cohesiveness properties, and temperature moderation ability
Of all the molecules that are significant to biology, which of the following are considered the most important?
Carbohydrates, lipids, proteins, and nucleic acids
Structure of carbohydrates:
Long chains, or polymers, of sugars
Function of carbohydrates:
-Storage, structure, and energy -Form the backbone of DNA and RNA
3 lipids:
Fatty acids, phospholipids, steroids
2 fatty acids:
Saturated and unsaturated
Saturated fats:
-Contain no double bonds -SOLID
Unsaturated fats:
-Contain one or more double bonds -LIQUID at room temperature
Phospholipids:
- Consist of 2 fatty acids of varying length bonded to a phosphate group
- Amiphipathic (hydrophillic and lipophillic)
How do phospholipids play a role in the cell membrane?
Their structure creates a barrier that protects the cell
Phospholipid structure:
-Phosphate group is charged and polar while the hydrocarbon tail of the fatty acids is non-soluble
Steroids:
Precursors to significant hormones and drugs
Most significant contributor to cellular function:
Proteins
Amino acids:
Polymers of 20 molecules
DNA
Unique molecule specific to a particular organism that contains code necessary for replication
RNA
Used to transfer info from DNA to protein level and as a messenger of the genetic code
Metabolic pathway:
Reactions that take place from high energy to low energy
Prokaryotic cells:
-Lack a nucleus -Do not contain membrane-bound organelles -Replicate via binary fission
Eukaryotic cells:
-Have a membrane-enclosed nucleus and contain membrane-bound organelles -Replicate via mitosis
Nucleus:
Contains DNA of the cells in chromosomes
Chromosomes:
Contain all the genetic info that stores instructions for the function of the cell
Ribosomes:
Read RNA and translate the genetic instructions to produce proteins
Bound ribosomes are found:
Attached to the endoplasmic reticulum
Free ribosomes are found:
In the cytoplasm
Rough ER:
Responsible for protein synthesis and membrane production
Smooth ER:
-Lacks ribosomes -Responsible for detoxification and metabolism of molecules
Golgi apparatus:
Packaging, processing, and shipping organelle that transports proteins from the ER throughout the cell
Lysosomes:
-Where intracellular digestion takes place -Hydrolyzes proteins, fats, sugars, and nucleic acids
Vacuoles:
Sacs used to phagocytose food and waste disposal
Plant vacuoles function as:
Storage, waste disposal, protection, and hydrolysis
2 organelles that produce cell energy:
Mitochondrion and chloroplasts
Mitochondria:
-Found in eukaryotic cells -Site of cellular respiration/ generating ATP
Chloroplasts:
-Found in plants -Site of photosynthesis
Most important component of the cells:
Cellular membrane
Cellular membrane:
Contributes to protection, communication, and passage of substances into and out of the cell
Cell membrane consists of:
Bilayer of phospholipids with proteins, cholesterol, and glycoproteins throughout
The sum of all chemical reactions that occur in an organism is:
Metabolism
Two catabolic pathways that lead to cellular energy production are:
Cellular respiration (aerobic) and fermentation (anaerobic)
Glycolysis:
Where does it take place?
- Anaerobic process
- Conversion of glucose to pyruvate
- Takes place in the cytosol of the cell
Glycolysis produces:
2 ATP, 2 pyruvate, 2 NADH
Citric acid cycle/ Kreb’s:
Where does it take place?
- Aerobic process
- Pyruvate is transported into a mitochondrion
- Takes place in the matrix of the mitochondria
Citric acid cycle/ Kreb’s produces:
2 ATP, 6 carbon dioxide, 6 NADH
Electron transport chain:
- Aerobic process
- Oxidation of the NADH molecules to produce oxygen and finally to produce water
Electron transport chain produces:
28-32 ATP
Overall number of ATP produced in glycolysis, Kreb’s, ETC:
32-36 ATP
2 stages of photosynthesis:
Light reaction and Calvin cycle
Light reactions:
Those that convert solar energy to chemical energy
All metabolic reactions in a cell are catalyzed by?
Enzymes
Phenotype:
What traits will be expressed (e.g. brown hair, blonde hair, red hair)
Genotype:
The genetic makeup of an organism (e.g. bb, Bb, or BB)
Calvin cycle:
Second stage of photosynthesis where NADH and ATP produced by light reactions are used to produce sugar.
Covalent bonds:
Attach the hydrogen atoms to the oxygen atom in a molecule of water
Hydrogen bonds:
Are what connect water molecules to other molecules
Photosynthesis:
Light energy is captured and used to convert water and carbon dioxide into oxygen and sugar through light reactions and the calvin cycle
Process of a light reaction:
The cell absorbs the light and uses the light energy to split a water molecule and transfer the electron, producing NADPH and ATP
Binary fission:
Process by which bacteria (prokaryotes) replicate.
The chromosome binds to the plasma membrane, where it replicates. As the cell grows, it pinches in two, producing two identical cells.
2 types of asexual reproduction:
Binary fission and mitosis
5 stages of mitosis:
Prophase Prometaphase Metaphase Anaphase Telophase
Interphase:
Phase the cell is in before meiosis and meiosis start. Chromosomes are duplicated and the cell prepares for division. The chromosomes are uncondensed.
Prophase:
Chromosomes are visibly separate with each duplicated chromosome having two sister chromatids.
Prometaphase:
Nuclear envelope begins to disappear, and the chromosomes begin to attach to the growing spindle.
Metaphase:
Chromosomes line up in the middle of the cell on the metaphase plate.
Anaphase:
The sister chromatids separate into individual chromosomes and are pulled apart. The separated chromatids are now each considered individual chromosomes.
Telophase:
The chromosomes gather on each side of the cell as it begins to pinch.
Pinching off in animal cells:
Cleavage furrow
Pinching off in plant cells:
Cell plate
Cytokinesis:
After mitosis is complete, the cell divides in two, producing two identical daughter cells (46 chromosomes, 46 chromotids each daughter cell)
After meiosis is complete, the cell divides in 4, producing 4 unique cells (23 chromosomes, 23 chromotids each cell)
In asexual reproduction:
The offspring originates from a single cell-> all cells produced to be identical
In sexual reproduction:
Two cells contribute genetic material to daughter cells -> resulting in a greater variation of cells
Mitosis:
- Responsible for growth, repair of damage, and replacement worn out cells
- Makes identical body and skin cells
Meiosis:
- Reduction division process that contributes to genetic variety
- Makes sperm and eggs cells (gametes)
Difference between mitosis and meiosis?
In meiosis prophase I, nonsister chromotids of homologous chromosomes cross over and transfer genetic info. In mitosis metaphase I, chromosomes line up in PAIRS in the middle.
Allele:
2 alternative variations of a genes
DNA discovered by:
Watson and Crick
Transcription:
An RNA strand complementary to the original strand of DNA is produced (mRNA)
Genetic material produced through transcription:
Messenger RNA (mRNA)
Where does the mRNA go?
Out of the nucleus-> ribosome-> cytosol or rough ER
Translation:
tRNA binds to mRNA to create a chain of amino acids (polypeptides)
tRNA:
Carries a specific amino acid and has an anti-codon on the opposite end to match up on the mRNA strand
Stop codon:
Chain of amino acids ends and is released into the cytoplasm, the protein folds onto itself and forms its complete comformation.
A cell from the heart muscle would more than likely contain an unusually high proportion of:
Mitochondria
Which part of cellular respiration produces the greatest amount of ATP?
ETC
Why is it important for cells to undergo mitosis?
Mitosis produces cells for growth and repair of body tissue
72 chromosomes undergo meiosis. How many chromosomes will be in each gamete?
36
Anabolic reactions:
Builds larger and more complex molecules from smaller ones
Catabolic reactions:
Larger molecules are broken down into smaller, simpler molecules
Meiosis 1 steps:
P1: Chromosomes condense and match up with homologous pairs to transfer DNA
M1: Homologous chromosomes line up in the middle of the cell in pairs
A1: Chromosomes are pulled away by spindle fibers
T1: Forms 2 new cells
Cytokinesis: Splits cytoplasm
Meiosis 2 steps:
P2: No homologous pairs of chromosomes or crossing over
M2: Chromosomes line up in a single file line
A2: Chromotids are pulled away
T2: Cell begins to divide into 4 cells
Cytokinesis: Splits cytoplasm to 4 cells
Human body cells have:
Human sex cell gametes have:
46
23
What is the typical result of mitosis in humans?
2 diploid cells
Haploid cell:
Diploid cell:
Both sets of homologous chromosomes (meiosis)
Same set of chromosomes (mitosis)
What is not produced in the Kreb’s cycle?
Oxygen
What kind of bond connects sugar and phosphate in DNA?
Covalent
3 steroids:
Cholestrol, estrogen, testosterone
What property is responsible for passage of water through a plant?
Cohesion
During which phase is the chromosome number reduced from diploid to haploid?
Meiosis I
Which form of water is the densest?
Liquid
What is the longest phase in the life of a cell?
Interphase
What is neccessary for cell diffusion?
Water
Which cell type has no nucleus?
RBC
What is the most general taxomic category?
Kingdom
Process by which organisms use energy:
Metabolism
When both parents give offspring the same allele, the offspring is ____ for that trait:
One dominant and one recessive trait, the offspring is ____ for that trait:
Homozygous
Heterozygous
Scientists suggest that evolution has occured through a process called:
Natural selection
Cellular heirarchy from simplest to most complex structure:
Cell, tissue, organ, organ system, organism
All living organisms on earth utilize:
A triplet genetic code
Exergonic reactions:
Create energy
During the S phase in the interphase stage of mitosis, what event is occuring?
Rapid DNA replication
How is the most amount of energy released from ATP?
When one phosphate group breaks off of ATP to form ADP and free phosphate
Light dependent reactions:
Hydrolysis reaction to provide electrols to chlorophyll and release of oxygen
Light independent reaction:
Energy produced from dependent reaction is stored as chemical bonds in glucose
Biological community formed as a response to physical environment?
Biome
Ex: Terrestrial and marine
Made up of all living organisms in a specific area, as well as nonliving components of the physical environment:
Ecosystem
