Biology Chapter: Protein Synthesis and Endomembrane System

Protein Synthesis Steps

• mRNA is first produced in the nucleus after DNA uncoils for transcription.
• Once formed, mRNA moves to the ribosome.
• Ribosomes then traverse the mRNA to synthesize proteins.
• tRNA transports amino acids to the ribosomes for assembling proteins.
• The final step is the formation of the polypeptide.

Endomembrane System Function

• Ribosomes on the rough ER synthesize proteins, which are packaged into transport vesicles.
• The Golgi apparatus receives these transport vesicles for modification.
• Modified proteins may be secreted via exocytosis.

Levels of Structural Organization in the Human Body

• The correct sequence from simplest to most complex:
  • Chemical level
  • Cellular level
  • Tissue level
  • Organ level
  • Organ system level
  • Organismal level

Homeostasis

• Defined as the maintenance of a relatively constant internal environment.

Negative Feedback Loop

• An effector responds to signals from the control center to maintain homeostasis.

Feedback Loop Scenario

• Increased body temperature serves as the stimulus in a feedback loop, observed through sweat gland activation helping to cool the body.

Positive Feedback Loop Example

• Breastfeeding illustrates a positive feedback loop where the stimulus (sucking) increases the response (milk production).

Gradient Concept

• A gradient exists when there is a higher concentration of a substance in one area compared to another, with the two areas connected.

Cell Communication Methods

• Cells primarily communicate through chemical messengers and electrical signals.

Core Principles of Homeostasis

• Metabolism is NOT one of the four core principles related to homeostasis.

Atomic Structure

• An atom with 15 electrons has 5 electrons in its outermost shell.
• An electrically neutral atom with an atomic number of 8 (mass number 17) has 8 protons.

Element Prediction

• The element identity of an atom is determined by the total number of protons it contains.

Common Elements in the Body

• The four most abundant elements constituting 96% of the body's mass are:
  • Oxygen
  • Nitrogen
  • Hydrogen
  • Carbon

Blood Plasma Composition

• A mixture of glucose dissolved in blood plasma is termed a solution.

Hydrogen Bond Formation

• Hydrogen bonds typically occur between polar molecules.

Inert Atoms

• An atom with an atomic number of 10 is considered inert due to a full outer electron shell.

Types of Chemical Bonds

• The strongest bond type is a double covalent bond.

Exchange Reactions

• An example of an exchange reaction is represented by the equation AB + CD → AD + BC.

Enzyme Function

• Enzymes enhance the speed of chemical reactions by lowering activation energy barriers.

Solubility of Compounds

• Compounds that have nonpolar covalent bonds are unlikely to dissolve in water.

Carbohydrate Building Block

• The monomer of carbohydrates is known as a monosaccharide.

Free Hydrogen Ion Binding

• Free hydrogen ions in a solution are typically bound by a base.

Buffer Function

• Buffers function to minimize fluctuations in pH levels when acids or bases are introduced into a solution.

Lipid Building Block

• Fatty acids serve as the fundamental building blocks of lipids.

Basis for Steroids

• Cholesterol forms the basis of the body's steroid compositions.

Amino Acid Linkage

• Amino acids are linked by peptide bonds which are type of polar covalent bond.

Protein Structure Types

• The alpha-helix and beta-pleated sheets represent secondary protein structures.

Nucleic Acid Example

• A chemical comprising a phosphate group, a nitrogenous base, and ribose sugar is identified as a nucleic acid.

Exergonic Reactions

• The digestion of food is classified as an exergonic process due to the release of energy when chemical bonds are broken.

Test your knowledge of key biological processes in this quiz covering the steps of protein synthesis and the function of the endomembrane system. Arrange the sequences in the correct order to demonstrate your understanding. Ideal for students and enthusiasts alike.