Anatomy and physiology 1 exam

The three main parts of the cell are

cell membrane, cytoplasm, and nucleus

 The fluid portion of the cytoplasm is the

cytosol

The sodium pump is an example of primary active transport. true or false

true

The basic structural unit of the plasma membrane is the

lipid bilayer

Integral proteins can function in the cell membrane in all of the following ways except

exocytes vesicle

A cell would lose water volume and shrink if placed in

hypertonic solution

what is not true about positive feedback

Is something which occurs daily and Brings body closer to homeostasis

Cytoskeleton

 network of protein filaments providing cellular shape & organization

Ribosomes

site of protein synthesis

Rough ER

site where secretory proteins and membrane molecules are made

Smooth ER

 functions in synthesizing fatty acids and steroids, helping liver cells release glucose into the bloodstream and detoxification

Golgi complex

modifies, sorts, packages, and transports molecules made in the RER

Lysosomes

membrane-enclosed vesicles of enzymes formed in the Golgi complex

Peroxisomes

vesicles with enzymes that oxidize organic substances

Mitochondria

functions in ATP generation

Cilia

microtubular structures moving materials along the cell’s surface

Centrosome

organizing center for growth of the mitotic spindle

Diffusion

the random mixing of particles in a solution due to the kinetic energy of the particles

Osmosis

movement of water from an area of higher to an area of lower water concentration through a selectively permeable membrane

Facilitated diffusion

passive transport in which a solute binds to a specific transporter on one side of the membrane and is released on the other side

Primary active transport

uses energy derived from the hydrolysis of ATP to change the shape of a transporter protein which ‘pumps’ a substance across a cellular membrane against its concentration gradient

Secondary active transport

indirectly uses energy obtained from the breakdown of ATP, involves symporters and antiporters

Vesicular transport

transport of substances either into or out of the cell by means of a small spherical membraneous sac formed by the budding off from existing membranes

Phagocytosis

endocytosis of large solid particles

Pinocytosis

 type of endocytosis that involves the nonselective uptake of tiny droplets of extracellular fluid

Exocytosis

movement of materials out of the cell by fusing of secretory vesicles with the plasma membrane

Receptor-mediated endocytosis

process that allows a cell to take specific ligands from the ECF by forming vesicles

transcytosis

uses energy derived from the hydrolysis of ATP to change the shape of a transporter protein which ‘pumps’ a substance across a cellular membrane against its concentration gradientuses energy derived from the hydrolysis of ATP to change the shape of a transporter protein which ‘pumps’ a substance across a cellular membrane against its concentration gradient

negative feedback

Negative feedback reverses a change to bring the body back to homeostasis. It is the most common type of feedback, stabilizing conditions by opposing the original stimulus. Examples include regulating body temperature, blood glucose, and blood pressure.

positive feedback

Positive feedback amplifies a change and moves the body further from homeostasis until a specific event is completed. It is rare, reinforces the stimulus, and usually requires an outside event to stop. Examples include childbirth, blood clotting, and nerve impulse conduction.

hierarchy of life

Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism → Population → Community → Ecosystem → Biosphere

homeostasis

Homeostasis is the body’s ability to maintain a stable internal environment despite changes in the external environment

important compounds in the body

proteins,carbs ,lipids, and nucleic acids

metabolism

Metabolism is the sum of all chemical reactions that occur in the body to maintain life

passive transport

Movement of substances without using cellular energy (ATP), driven by concentration gradients. Examples are moving substances from high → low concentration (down the gradient) and does not require atp.

active transport

Movement of substances using cellular energy (ATP), often against concentration gradients. Moves substances from low → high concentration (against the gradient). does require energy.

endocytosis

The process by which a cell takes in substances by engulfing them in a vesicle formed from the plasma membrane. Its purpose is to bring large molecules, particles, or fluids into the cell.

Exocytosis

The process by which a cell releases substances to the outside is by fusing a vesicle with the plasma membrane. Its purpose is to remove waste, secrete hormones, neurotransmitters, or enzymes.

what is the difference between symport and antiport

Symport is a type of secondary active transport where two substances move in the same direction across the membrane. Antiport is a type of secondary active transport where two substances move in opposite directions across the membrane.

what is the difference between a hypertonic, hypotonic, and isotonic solution

A hypertonic solution has a higher solute concentration than the cell, causing water to leave the cell and the cell to shrink. A hypotonic solution has a lower solute concentration than the cell, causing water to enter the cell and the cell to swell. An isotonic solution has the same solute concentration as the cell, so there is no net movement of water and the cell maintains its shape.

osmosis

Osmosis is the passive movement of water across a selectively permeable membrane from an area of higher water concentration (lower solute) to an area of lower water concentration (higher solute).

diffusion

Diffusion is the passive movement of molecules or ions from an area of higher concentration to an area of lower concentration until they are evenly distributed. No energy needed!!

what are the ions in the body and there roles

The main cations are sodium (Na⁺, fluid balance & nerves), potassium (K⁺, nerves & muscles), calcium (Ca²⁺, bones, muscles, clotting), magnesium (Mg²⁺, enzymes & nerves), and hydrogen (H⁺, pH). The main anions are chloride (Cl⁻, fluids & stomach acid), bicarbonate (HCO₃⁻, pH buffer), phosphate (PO₄³⁻, ATP, DNA, bones), and sulfate (SO₄²⁻, proteins & connective tissue).

What are the components of a cell, and what are their specific functions

• Plasma membrane: controls entry/exit of substances

• Cytoplasm: fluid and organelles inside the cell

• Nucleus: stores DNA, controls cell activities

• Ribosomes: make proteins

• Rough ER: makes proteins for secretion/membranes

• Smooth ER: makes lipids, detoxifies, regulates glucose

• Golgi apparatus: modifies, sorts, and packages molecules

• Mitochondria: produce ATP

• Lysosomes: digest waste

• Peroxisomes: break down toxins

• Cytoskeleton: provides shape, structure, and movement

• Centrosome: organizes microtubules for cell division

• Cilia/Flagella: move cells or materials along their surface

What is the difference between DNA and RNA?

DNA stores genetic information and is double-stranded, with the sugar deoxyribose and bases A, T, C, G. RNA is usually single-stranded, has the sugar ribose, and uses the bases A, U, C, G; it helps carry out protein synthesis.

what makes up a nucleotide

A nucleotide is made of three components: a phosphate group, a five-carbon sugar (deoxyribose in DNA or ribose in RNA), and a nitrogenous base (A, T/U, C, or G).

What happens when the Na-K pump is on? or when its off

When the Na⁺-K⁺ pump is on, it uses ATP to move 3 sodium ions out of the cell and 2 potassium ions in, maintaining the proper ion gradients, resting membrane potential, and cell volume. When it is off, sodium builds up inside and potassium outside, disrupting ion balance, cell function, and potentially causing swelling or depolarization.

Describe the characteristics of the plasma membrane.  What makes it up?  What is its importance?

The plasma membrane is a flexible, selectively permeable barrier that surrounds the cell. It is mainly made of a phospholipid bilayer, cholesterol, integral and peripheral proteins, and glycolipids. It regulates what enters and exits the cell, provides structural support, allows communication with other cells, and helps maintain homeostasis.

  The functions of proteins in our body.

Proteins provide structure (such as collagen in connective tissue), act as enzymes to speed up chemical reactions, serve as transporters (like hemoglobin), function as antibodies in the immune system, act as hormones (like insulin), enable muscle contraction (via actin and myosin), and help maintain fluid and pH balance.

What are enzymes?  How do they work?

Enzymes are proteins that act as biological catalysts, speeding up chemical reactions without being consumed. They work by lowering the activation energy needed for a response and binding specific substrates at their active sites, converting them into products efficiently.

  Describe the properties of water.  Give examples of how these versatile molecules illustrate the properties.

Water is polar, allowing it to form hydrogen bonds, which makes it a solvent for ions and polar molecules, like salt or glucose. It has a high heat capacity, helping maintain body temperature. Water is also reactive in chemical reactions, like hydrolysis or dehydration synthesis, and lubricates joints and organs, reducing friction.