Cell Structure and Organelles

Cells

Cell Structure

• Cell Membrane: semi-permeable membrane that separates cell from environment
• Cytoplasm: jelly-like substance inside cell membrane where metabolic processes occur
• Nucleus: control center of cell where DNA is stored
• Mitochondria: organelles responsible for generating energy for cell through cellular respiration
• Ribosomes: site of protein synthesis
• Lysosomes: contain digestive enzymes that break down and recycle cellular waste and foreign substances

Cell Functions

• Metabolism: process of converting energy and nutrients into cellular components
• Photosynthesis: process of converting light energy into chemical energy (occurs in chloroplasts)
• Cell Division: process of cell growth and reproduction (mitosis and meiosis)
• Cell Signaling: process of communication between cells through signaling pathways

Genetics

DNA Structure

• Double Helix: twisted ladder structure of DNA consisting of two complementary strands
• Nucleotides: building blocks of DNA consisting of sugar, phosphate, and nitrogenous bases (A, C, G, and T)
• Hydrogen Bonding: weak bonds between nitrogenous bases that hold DNA strands together

Genetic Inheritance

• Genotype: genetic makeup of an individual (pair of alleles)
• Phenotype: physical expression of genotype (traits)
• Dominant and Recessive Alleles: dominant alleles are always expressed, recessive alleles are only expressed when paired with another recessive allele
• Mendel's Laws: laws of inheritance that describe how alleles are passed down from generation to generation

Gene Expression

• Transcription: process of creating RNA copy of DNA sequence
• Translation: process of using RNA sequence to build protein
• Gene Regulation: process of controlling gene expression through transcription factors and other mechanisms

Cell Biology

Cell Structure

• The cell membrane is a semi-permeable membrane that separates the cell from its environment and regulates what enters and leaves the cell.
• Cytoplasm is a jelly-like substance inside the cell membrane where metabolic processes occur, including glycolysis, protein synthesis, and cell signaling.
• The nucleus is the control center of the cell where DNA is stored, and it plays a crucial role in regulating cell growth and reproduction.
• Mitochondria are organelles responsible for generating energy for the cell through cellular respiration, the process of converting glucose into ATP.
• Ribosomes are the site of protein synthesis, where mRNA is translated into a specific sequence of amino acids.
• Lysosomes contain digestive enzymes that break down and recycle cellular waste and foreign substances, maintaining cellular homeostasis.

Cell Functions

• Metabolism is the process of converting energy and nutrients into cellular components, including carbohydrates, proteins, and fats.
• Photosynthesis is the process of converting light energy into chemical energy, occurring in chloroplasts, which are present in plant cells.
• Cell division is the process of cell growth and reproduction, involving mitosis and meiosis, which are essential for development, tissue repair, and the transmission of genetic information.
• Cell signaling is the process of communication between cells through signaling pathways, which involve the transmission of signals from one cell to another, influencing various cellular processes.

Genetics

DNA Structure

• DNA has a double helix structure, consisting of two complementary strands held together by hydrogen bonds between nitrogenous bases.
• Nucleotides are the building blocks of DNA, consisting of sugar, phosphate, and nitrogenous bases (A, C, G, and T), which are arranged in a specific sequence to encode genetic information.
• Hydrogen bonding between nitrogenous bases is a weak bond that holds the DNA strands together, but can be easily broken and reformed during DNA replication and transcription.

Genetic Inheritance

• The genotype is an individual's genetic makeup, consisting of a pair of alleles (one inherited from each parent) that determine the expression of a particular trait.
• The phenotype is the physical expression of an individual's genotype, resulting from the interaction of the genotype with the environment.
• Dominant alleles are always expressed, while recessive alleles are only expressed when paired with another recessive allele, leading to a predictable pattern of inheritance.
• Mendel's laws of inheritance describe how alleles are passed down from generation to generation, including the laws of segregation, independent assortment, and dominance.

Gene Expression

• Transcription is the process of creating an RNA copy of a DNA sequence, which serves as a template for protein synthesis.
• Translation is the process of using the RNA sequence to build a protein, which involves the assembly of amino acids in a specific sequence.
• Gene regulation is the process of controlling gene expression through transcription factors, which bind to specific DNA sequences to either stimulate or inhibit gene expression, and other mechanisms that influence gene expression.

Learn about the different components of a cell, including the cell membrane, cytoplasm, nucleus, mitochondria, ribosomes, and lysosomes. Understand their functions and roles in the cell.