Plant Cell Biology: Membranes, Metabolism, and Transport
Cell Membranes: Composition and Structure
Cell membranes are lipid bilayers composed of lipids, proteins, and fatty acids. Their mosaic and fluid structure enables component sharing.
Plant Cell Organelles and Their Functions
Nucleus
Controls genetic material replication and transcription.
Plastids
Conduct photosynthesis.
Mitochondria
Carry out cellular respiration.
Endoplasmic Reticulum
Facilitates protein transport and processing.
Golgi Apparatus
Synthesizes non-cellulosic structural polysaccharides.
Vacuoles
Maintain
Read MorePhotosynthesis: Electron Transport and Carbon Fixation
Photosynthesis: Non-Cyclic Electron Transport
Non-Cyclic Electron Transport
In the light phase of photosynthesis, electrons are transported from H2O to NADP+ through the photosynthetic chain. This transport isn’t spontaneous; light energy, captured by pigments in photosystems I and II, is needed. Water molecules break down (photolysis), providing electrons to the chain and releasing O2 as a byproduct.
This transport can be divided into three segments:
Photosystem I (PSI) and NADPH Reduction
A photon
Read MoreHuman Circulatory System: Blood, Heart, Vessels
The Circulatory System
The circulatory system has several functions:
- Brings food and oxygen to the cells.
- Collects metabolic wastes (removed by the kidneys as urine).
- Exchanges air (rich in carbon dioxide) in the lungs.
All this work is done by the blood, which constantly circulates. Additionally, the circulatory system:
- Is involved in the body’s defense system.
- Regulates body temperature.
- Transports hormones.
Blood
Blood is the fluid circulating throughout the body via the circulatory system. This system
Read MoreDisease, Health, and Lifestyle: Understanding the Connections
Disease and Its Types
Concept and Classification
Disease is a disorder causing physical or mental disturbances in normal bodily functions. Pathology refers to the changes that occur in the body due to disease.
Classifications of Diseases
- Non-infectious Diseases: Caused by factors other than pathogens. This includes non-communicable diseases like injuries and some genetic disorders.
- Infectious Diseases: Caused by pathogenic bacteria, viruses, fungi, or protozoa. These are the most frequent causes of human
Health and Disease: A Comprehensive View
Health and Socioeconomic Development
Throughout history, we’ve learned that poverty and ill health are intertwined, creating a vicious cycle. Health programs are crucial for economic growth. Developed countries have made significant strides in improving public health by:
- Increasing healthcare spending for all citizens.
- Expanding health coverage.
- Allocating resources efficiently.
Health Determinants
Our health is influenced by several factors, some modifiable, others not.
Environment
- Physical Contaminants:
Kingdom Classification: Fungi, Plants, and Animals
Fungi
Characteristics
Fungi can be unicellular or multicellular organisms. Their cell walls are composed of chitin, a polysaccharide. Multicellular fungi form a network of filaments called hyphae, which make up the mycelium, the feeding structure of the fungus. Fungi are heterotrophic, meaning they obtain nutrients by absorbing them from their environment.
Nutritional Modes
- Saprobiontes: Obtain food from dead organic matter by secreting digestive enzymes that break down complex compounds into simpler