Midterm1 Flashcards
Describe properties of living organisms
- Living organisms must be able to grow, metabolize substances, reproduce, and respond to external stimuli.
- Living organisms contain a common set of biological molecules, are composed of cells, and can maintain homeostasis and evolve
List the components of water and some of the properties that make it important in living organisms
- water consists of 1 oxygen and 2 hydrogen atoms
- Water is a good solvent in part because of its polarity and ability to form hydrogen bonds. Hydrogen bonding in water facilitates chemical reactions, promotes cohesion, and allows fo rheat absorption.
- The polarity of water also facilitates the dissolving of salts
- water has a neutral pH.
pH scale
measure of the relative percentages of ions in a solution and ranges from 0 (acidic or rich in hydrogen ions) to 14 (basic or rich in hydroxyl ions)
describe how structure affects chemical bonding
- Chemical bonding depends on an elements electron configuration. Electrons closer to the nucleus have less energy than thos that are farther away from the nucleus.
- Atoms that have space in their valence shell form chemical bonds.
hydrogen bond
weak attraction between hydrogen atoms and oxygen atoms in adjacent molecules
covalent bond
bond that forms when atoms share electrons. Tend to be strong bonds
Ionic bond
bonds formed between positively and negatively charge ions. Tend to be weaker bonds.
Importance of Carbon
life on earth based on carbon chemistry. the element carbon can bond with up to 4 other elements.
carbohydrates
function in energy storage and play structural roles. They can be single-unit monosaccharides or multiple unit polysaccharides with sugar monomers joined by covalent bonds
proteins
play structural, enzymatic, and transport roles in cells. composed of amino acid monomers joined by covalent bonds
lipids
partially or entirely hydrophobic and come in three forms. Fats are glycerol covalent bond to 3 fatty acids. fats store energy.
Phospholipid
lipid composed of glycerol, 2 fatty acids, and a phosphate group. important structure component of cell membranes
steroid
composed of 4 fused rings. Cholesterol is a steroid found in some animal cell membranes. Other steroids act as hormones
Nucleic acids
polymers of covalently bonded nucleotides, each composed of sugar, a phosphate, and a nitrogen containing base
prokaryotic cell
cell lacking a membrane bound nucleus
eukaryotic cells
cells containing membrane bound nucleus
mitochondria and chloroplasts
energy conversions
lysosomes
breakdown of macromolecules
ribosomes
sites for protein synthesis
smooth endoplasmic reticulum
synthesizes lipids
Golgi apparatus
sorts proteins and sends them to their cellular destination
centrioles
help cell divide
macromolecules in living organisms
carbohydrates, proteins, lipids, and nucleic acids
metabolism
all of the chemical processes that occur in the cell including breakdown, synthesis and excretion
homeostasis
roughly constant internal environment
enzymes
proteins that accelerate and help regulate all chemical reactions that build up and break down molecules inside the cell
amino acids
monomer subunits of proteins. 20 commonly occurring carbons, hydrogens, oxygens, nitrogen, and side groups
nucleotide
sugar, phosphate, nitrogen containing base
macronutrients
nutrients that are required in large amounts including water, carbohydrates, proteins, and fats
passive transports
includes simple diffusion and facilitated diffusion (diffusion through proteins) .
Always moves substance with their concentration gradient and does not require energy.
osmosis
diffusion of water across a membrane
active transport
active transport is an energy requiring process that requires proteins in cell membranes to move substances against their concentration gradient