Lipid metabolism involves synthesis and degradation of fats for energy. Most dietary fats are triglycerides and cholesterol. Lipids need solubilization before metabolism begins
Gluconeogenesis synthesizes glucose from non-carbohydrate carbon substrates. Mainly occurs in liver and kidney cortex of vertebrates. Used to maintain blood sugar levels in humans and animals
Hummingbirds are small, flight-capable birds native to Americas. Family Trochilidae contains approximately 366 species. World's smallest bird is bee hummingbird at 5 cm length. Males have widest plumage color diversity among birds
Organisms are classified into three domains and six kingdoms. Classification based on cell type, nutrient acquisition, and reproduction. Modern classifications use cladistics, noting kingdoms aren't monophyletic
Calorie burn depends on age, gender, weight, and current activity level. MET (metabolic equivalent for task) estimates energy use during specific activities. Formula: Total calories = Duration * (MET * 3.5 * weight / 200)
Appetite is controlled by ghrelin (hunger) and leptin (fullness) hormones. Sudden appetite loss may indicate serious health conditions. Children and older adults naturally lose appetite