Cell Structure and Cellular Processes

Cells

• Cell Structure:
  • Plasma membrane: semi-permeable membrane that separates cell from environment
  • Cytoplasm: jelly-like substance inside cell membrane
  • Nucleus: contains genetic material (DNA)
  • Mitochondria: generates energy for cell
  • Endoplasmic reticulum: involved in protein synthesis and transport
  • Lysosomes: contains digestive enzymes
• Cellular Processes:
  • Metabolism: conversion of energy and nutrients
  • Photosynthesis: process by which plants convert light energy into chemical energy
  • Cell division: process of cell growth and reproduction
  • Cellular respiration: process of generating energy from glucose

Genetics

• DNA Structure:
  • Double helix model: two strands of nucleotides twisted together
  • Nucleotides: composed of sugar, phosphate, and nitrogenous bases (A, C, G, and T)
• Genetic Inheritance:
  • Mendel's laws: rules governing how traits are inherited
  • Dominant and recessive genes: determine expression of traits
  • Genotype: genetic makeup of an individual
  • Phenotype: physical expression of genotype
• Genetic Variation:
  • Mutation: change in DNA sequence
  • Genetic drift: random change in gene frequency
  • Gene flow: movement of genes between populations

Ecosystems

• Ecosystem Components:
  • Biotic factors: living organisms (plants, animals, microorganisms)
  • Abiotic factors: non-living components (light, temperature, water, soil)
  • Producers: organisms that convert light energy into chemical energy
  • Consumers: organisms that obtain energy by consuming other organisms
• Ecosystem Processes:
  • Energy flow: transfer of energy from one organism to another
  • Nutrient cycling: movement of nutrients through ecosystem
  • Decomposition: breakdown of organic matter
  • Succession: process of ecosystem change over time

Evolution

• Mechanisms of Evolution:
  • Natural selection: process by which populations adapt to environment
  • Genetic drift: random change in gene frequency
  • Mutation: change in DNA sequence
  • Gene flow: movement of genes between populations
• Evidence for Evolution:
  • Fossil record: chronological record of extinct species
  • Comparative anatomy: study of similarities and differences between species
  • Molecular biology: study of DNA and protein similarities between species
  • Biogeography: study of geographic distribution of species

Cells

• Plasma membrane is a semi-permeable membrane that separates the cell from its environment
• Cytoplasm is a jelly-like substance inside the cell membrane where metabolic activities occur
• Nucleus contains genetic material (DNA) and is responsible for controlling cell growth and reproduction
• Mitochondria generates energy for the cell through cellular respiration
• Endoplasmic reticulum is involved in protein synthesis and transport
• Lysosomes contain digestive enzymes and break down foreign substances and cellular waste

Genetics

• DNA is structured as a double helix, with two strands of nucleotides twisted together
• Nucleotides are composed of sugar, phosphate, and nitrogenous bases (A, C, G, and T)
• Mendel's laws govern how traits are inherited, including the law of segregation and the law of independent assortment
• Dominant and recessive genes determine the expression of traits, with dominant genes overriding recessive genes
• Genotype refers to the genetic makeup of an individual, while phenotype refers to the physical expression of that genotype
• Genetic variation can occur through mutations, genetic drift, or gene flow

Ecosystems

• Biotic factors in an ecosystem include living organisms such as plants, animals, and microorganisms
• Abiotic factors include non-living components such as light, temperature, water, and soil
• Producers convert light energy into chemical energy through photosynthesis
• Consumers obtain energy by consuming other organisms, and can be classified into primary, secondary, or tertiary consumers
• Energy flows from one organism to another through food chains and food webs
• Nutrient cycling involves the movement of nutrients through the ecosystem, with decomposers playing a key role in releasing nutrients back into the environment
• Decomposition is the breakdown of organic matter, while succession is the process of ecosystem change over time

Evolution

• Natural selection is the process by which populations adapt to their environment, leading to the survival and reproduction of individuals with favorable traits
• Genetic drift is a random change in gene frequency, which can lead to the loss of genetic variation
• Mutations are changes in DNA sequence, which can result in new traits or changes to existing ones
• Gene flow is the movement of genes between populations, which can lead to genetic changes and increased variation
• The fossil record provides a chronological record of extinct species, with transitional fossils providing evidence for evolution
• Comparative anatomy and molecular biology reveal similarities and differences between species, providing evidence for evolution
• Biogeography, the study of the geographic distribution of species, also provides evidence for evolution

Explore the components of a cell, including the plasma membrane, cytoplasm, nucleus, mitochondria, endoplasmic reticulum, and lysosomes. Learn about cellular processes like metabolism and photosynthesis.