Studied by 24 people
What do all living things have in common?
Life Processes:
transport
respiration
synthesis
growth
reproduction
excretion
nutrition
What is homeostasis?
Maintenance of a constant (stable) environment
What is transport?
Movement of materials throughout the entire organism
What is respiration?
Processes that releases energy from food
What is synthesis?
Combining of simple substances to form more complex substances (Ex: DNA and enzymes
What is growth?
Increase in size and / or number of cells in organism
What is reproduction?
continue species (sexual or asexual)
What is excretion?
Removal of toxic waste
What is nutrition?
Process of taking in (or making) organic nutrients and then breaking them down to fuel all the life processes (autotrophs and heterotrophs)
What does “metabolism” mean?
all of the chemical reactions that take place in organism (continuous use and release of energy)
What are the two types of metabolism?
Exergonic —> “fast” metabolism
Endergonic —> “slow” metabolism
What is the difference between positive and negative feedback?
Positive —> In a positive feedback system, the output ENHANCES the original stimulus?
Negative —> In a negative feedback system, the output reduces the original effect of the stimulus.
Is this a positive or negative feedback mechanism? Ex: During childbirth stretching of the uterus triggers the secretion of the hormone oxytocin, which stimulates the uterine contractions and speeds up labor
Positive Feedback
What is fight or flight response?
Physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.
Needed for survival
Automatic, caused by sympathetic nervous system
What causes the fight or flight stress response?
Adrenaline (short term stress), Cortisol (long term stress)
Why is adrenaline important during our fight and flight response?
Response to life threating situation (In other words, finds the balance between excitement and inhibition, helping you live).
What are the properties of water? (why are they important?)
Polarity (water is a polar molecule, this polarity allows water molecules to form hydrogen bonds with each other)
Solvent properties (This property is crucial for biological and chemical processes because it allows for the transport of nutrients, minerals, and other molecules in living organisms)
Cohesion and Adhesion (Water molecules exhibit cohesion, sticking together due to hydrogen bonding. Adhesion refers to water's ability to stick to other substances. Both cohesion and adhesion contribute to capillary action and surface tension)
High Specific Heat (Meaning it can absorb and retain a significant amount of heat without a large change in temperature. This property helps regulate temperature in organisms and ecosystems)
High Heat of Vaporization (Substantial amount of heat to change from a liquid to a gas. This property contributes to the cooling effect of sweating in animals and transpiration in plants)
Density Anomaly (This causes ice to float on water, and it is crucial for the survival of aquatic organisms during winter)
Universal Solvent (Can dissolve a wide variety of substances, facilitating chemical reactions and biological processes)
Surface Tension (Due to hydrogen bonding at the surface. This allows some insects, like water striders, to "walk" on the surface of water)
Carbohydrates (elements found in each molecule and the monomers/ polymers for the molecule)
made up of carbon (C), hydrogen (H), and oxygen (O) atoms. The general chemical formula for carbohydrates is CnH2nOn, where n represents the number of carbon atoms.
Monomer: Monosaccharides
Polymer: Disaccharide (two monosaccharide units) and Polysaccharides (multiple units of monosaccharide units)
What are the functions of carbohydrates?
Energy Source: When consumed, carbohydrates are broken down into glucose (or other monosaccharides), which can be used by cells for energy through cellular respiration.
Energy Storage: Excess glucose is converted into storage forms for future energy needs. In animals, glucose is stored as glycogen in the liver and muscles, while in plants, it is stored as starch.
Structural Support:
Cellulose: Found in the cell walls of plants, providing rigidity and structural support to plant cells.
Chitin: Present in the exoskeletons of arthropods (such as insects and crustaceans) and in the cell walls of fungi, providing structural support.
Cellular Communication: Carbohydrates on the surface of cells play a crucial role in cellular recognition and communication. They are involved in cell adhesion, immune responses, and signal transduction.
Nucleotide Sugars in DNA and RNA: Deoxyribose and ribose, which are carbohydrates, are components of DNA and RNA nucleotides, respectively. These nucleotides are fundamental in genetic information storage and transfer.
Blood Sugar Regulation: Carbohydrates, especially complex carbohydrates with fiber, play a role in regulating blood sugar levels.
Dietary Fiber: Certain carbohydrates, such as soluble and insoluble fiber, contribute to digestive health. Fiber aids in proper digestion, absorption of nutrients, and helps prevent constipation.
Lipids (elements found in each molecule and the monomers/ polymers for the molecule)
The main elements found in lipid molecules are carbon (C), hydrogen (H), and oxygen (O). The specific types and arrangement of atoms vary among different classes of lipids.
Fatty acids are often considered the building blocks or components that contribute to the structure of many lipids.A fatty acid is a long hydrocarbon chain with a carboxyl group (COOH) at one end.
Fatty acids are a common component in the formation of various lipid molecules, including triglycerides, phospholipids, and others.
What are the functions of lipids?
Energy Storage: They can store large amounts of energy in the form of fatty acids, which can be released when needed through processes like oxidation.
Structural Component of Cell Membranes: Phospholipids are crucial components of cell membranes. They form the lipid bilayer that constitutes the basic structure of cell membranes, providing a barrier that separates the interior of the cell from its external environment.
Insulation and Temperature Regulation: Lipids, especially adipose tissue, act as insulators that help retain heat in the body. Additionally, they provide a protective layer around organs.
Cushioning and Protection: Adipose tissue serves as a cushion around organs
Precursors for Hormones: Lipids are precursors for the synthesis of various hormones, including steroid hormones. For example, cholesterol is a precursor for the synthesis of hormones like estrogen and testosterone.
Cell Signaling: Lipids play a role in cell signaling and communication. Lipid-derived signaling molecules, such as eicosanoids, are involved in processes like inflammation, immune response, and blood clotting.
Waterproofing and Protection: Lipids, such as waxes, are involved in waterproofing and protection of surfaces. For example, lipids on the surface of leaves help prevent water loss in plants.
Proteins (elements found in each molecule and the monomers/ polymers for the molecule)
Contains carbon, hydrogen, oxygen, and nitrogen (sometimes sulfur)
Monomers: Amino Acids (Amino acids are organic molecules that contain an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (often denoted as "R")).
Polymers: Polypeptide chains (Amino Acid—>Dipeptide + H20 —> Polypeptide + H20
What are the functions of proteins?
Enzymes (Organic catalysts, start and speed up reactions, are not used up in a reaction, get recycled)
Motor / Contractile Proteins (movement of cilia and flagella)
Immune Defense (Antibodies are special proteins made by white blood cells that inactivate and destroy viruses and bacteria. antibodies are specific.
Transport Proteins (carry molecules into and out of cells, or throughout body. Ex: Hemoglobin, protein in blood cells that carry oxygen to all cells).
Structural Proteins (collagen, keratin makes up hair & cells)
Hormones and Signaling (Insulin—> protein hormone that regulates sugar in bloodstream. Receptors built into the membrane all cells, which detect signaling molecules released by other cells).
Nucleic Acids (elements found in each molecule and the monomers/ polymers for the molecule)
Carbon, Hydrogen, Oxygen, Phosphorus, and Nitrogen.
Monomer: Nucleotides
Polymer: Deoxyribonucleic Acids, Ribonucleic Acid
What are the functions of nucleic acids?
Genetic Information Storage:
DNA: In eukaryotic cells, DNA is the genetic material that carries the instructions needed for the development, functioning, growth, and reproduction of all living organisms. It stores the genetic information in the form of a double-stranded helical structure.
Genetic Information Transmission:
DNA Replication: Before cell division, DNA is replicated to ensure that each daughter cell receives a complete set of genetic instructions.
Gene Expression:
Transcription: DNA serves as a template for the synthesis of RNA through a process called transcription. RNA molecules, specifically messenger RNA (mRNA), carry the genetic code from the DNA to the ribosomes in the cytoplasm.
Translation: The information in mRNA is then translated into proteins by the cellular machinery. Transfer RNA (tRNA) and ribosomal RNA (rRNA) are also involved in the process of translation.
Protein Synthesis:
RNA: RNA is involved in protein synthesis. mRNA carries the genetic code from DNA to the ribosomes, where proteins are synthesized. tRNA brings amino acids to the ribosomes, ensuring the correct sequence of amino acids in the growing polypeptide chain.
5. Energy Transfer:
Adenosine Triphosphate (ATP): ATP, a nucleotide, is a key molecule for energy transfer in cells. It stores and releases energy during cellular processes, such as metabolism and cell signaling.
Storage of Information for Evolution:
Mutations: Changes in the nucleotide sequence of DNA through mutations provide the raw material for evolution, allowing for the generation of genetic diversity over time.
What is the relationship between nucleic acids and proteins?
The relationship between nucleic acids and proteins is central to the flow of genetic information and the synthesis of proteins, which are key components of living organisms.
Storage of genetic information
Transcription
Translation
Genetic Code
What is transcription? Where does it occur in a cell? Which molecules are involved?
Transcription —> process of creating messenger RNA (mRNA) from the DNA of our chromosomes.
Occurs in nucleus
Molecules Involved:
DNA:
Role: DNA serves as the template for transcription. The specific segment of DNA that is transcribed is called a gene. The DNA sequence contains the genetic information that will be transcribed into RNA.
RNA Polymerase:
Enzyme: RNA polymerase is the enzyme responsible for catalyzing the synthesis of RNA from a DNA template. It reads the DNA template in the 3' to 5' direction and synthesizes the complementary RNA molecule in the 5' to 3' direction.
What are exons and introns? How is mRNA edited?
Exons and Introns:
Exons: Exons are the coding regions of a gene that contain the information necessary to code for a protein. They are expressed and retained in the final mRNA.
Introns: Introns are non-coding regions of a gene that do not directly code for proteins. They are transcribed into pre-mRNA but are removed during mRNA processing.
mRNA Editing:
Process: mRNA editing involves modifications to the pre-mRNA transcript before it becomes mature mRNA. This includes the removal of introns through a process called splicing.
Splicing: Removes introns and joins exons together.
What is translation? How are mRNA, tRNA, involved?
Translation:
Definition: Translation is the process in which the information carried by mRNA is used to synthesize a protein.
Location: It occurs in the cytoplasm on ribosomes.
mRNA in Translation:
Role: mRNA carries the genetic code from DNA to the ribosomes.
Information: The sequence of codons in mRNA specifies the sequence of amino acids in the protein.
tRNA in Translation:
Role: tRNA brings amino acids to the ribosomes during translation.
Structure: Each tRNA has an anticodon region that base-pairs with the complementary codon on mRNA.
Amino Acid Attachment: Amino acids are attached to tRNA through aminoacyl-tRNA synthetases.
What is a gene mutation?
A gene mutation is a permanent alteration in the DNA sequence that makes up a gene. Gene mutations can occur spontaneously or be induced by various external factors such as radiation, chemicals, or errors during DNA replication. These mutations can affect the normal function of a gene and may have different consequences, depending on their nature and location.
Different types of gene mutations:
Point Mutations:
Substitution: A single nucleotide is replaced by another. This can lead to different amino acids in the protein sequence or may not affect the protein at all, depending on the nature of the substitution.
Insertions and Deletions (Indels):
Insertion: One or more nucleotides are added to the DNA sequence.
Deletion: One or more nucleotides are removed from the DNA sequence. Both insertions and deletions can result in a frameshift mutation, altering the reading frame of the gene.
Inversions and Translocations:
Inversion: A segment of the DNA is reversed.
Translocation: A segment of DNA is moved from one location to another, either within the same chromosome or between different chromosomes.
Repeat Expansions:
Expansion of Repeat Sequences: Certain regions of the DNA may contain repeating sequences. In some cases, these repeats can expand, leading to disorders known as repeat expansion diseases.
Some mutations may be neutral or silent, meaning they do not affect the function of the protein.
What is ATP? How is it used to do work in cells?
Adenosine Triphosphate (ATP) is a high-energy molecule that serves as the primary currency for energy transfer within cells. It stores and releases energy through the hydrolysis of its phosphate bonds, providing the necessary energy for various cellular processes and reactions.
ATP in cells works by releasing energy when its high-energy phosphate bonds are hydrolyzed, providing the necessary energy for cellular processes. This energy is then utilized by cells to drive various activities such as muscle contraction, active transport, and biosynthesis.
What is an enzyme?
An enzyme is a biological molecule, typically a protein, that acts as a catalyst to facilitate and accelerate chemical reactions within living organisms. Enzymes lower the activation energy required for a reaction to occur, thereby increasing the rate of the reaction without being consumed or permanently altered in the process.
Why are enzymes important in living things?
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What is a substrate?
A substrate is a molecule upon which an enzyme acts, serving as the specific reactant in a catalyzed chemical reaction.
How do enzymes work?
Note
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