Ch 2: Terms Pertaining to the Body as a Whole

Cell

Fundamental unit of all living things (animal or plant). Everywhere in human body — every tissue, every organ, made up of these indv units

Cell membrane

surrounds and protects cell, also regulates what passes into and out of cell

Nucleus

Controls operations of cell. Directs cell division and determines structure and function of cell. Contains chromosomes

Ribosomes

Small granules on endoplasmic reticulum that arrange AA on ER to make proteins.

Chromosomes

Rod-like structures w/i nucleus. All human body cells (except for sex cells) contain 23 pairs. Sex cells only have 23 unpaired.

Genes

Regions of DNA w/i each chromosome

DNA

regulates activities of cell according to its sequence (arrangement into genes) on each chromosome

Karyotype

Photograph of an indv’s chromosomes, arranged by size, shape, & #. Can determine whether chromosomes are normal

Trisomy 21

extra copy of chromosome 21 (down)

Cytoplasm

includes all of material outside nucleus & enclosed by cell membrane. Carries on work of the cell. Contains specialized apparatus to supply chemkical needs of cell

cyt/o

Cell

-plasm

formation

Mitochondria

Small rod-shaped bodies that provide the principal source of energy for the cell. Use nutrients & oxygen to releasde energy that’s stored in food

Catabolism

chemical process where complex foods (sugar & fat) broken down into simpler substances & energy is released by mitochondria. process provides energy for cells to do work of body

Cata-

down

Endoplasmic reticulum

network of canals w/i cell

Ribosomes

attached to endoplasmic reticulum. Build long chains of proteins

Anabolism

process of building up large proteins from small protein pieces (AA). Occurs on endoplasmic reticulum

Ana-

up

Which two processes make up cell’s metabolism

anabolism & catabolism

Metabolism

total of chemical processes occurring in a cell

Slow vs fast metabolism

Slow = foods burned slowly & fat accumulates in cells

Fast = foods used up quickly & energy is released

Cell membrane

Structure surrounding and protecting cell. Determines what enters and leaves cell

Anabolism - proteins made in cells

Instructions for making specific proteins begin in the nucleus as a DNA code. The code is transmitted to

mRNA (messenger RNA), which travels to the endoplasmic reticulum and ribosomes. The ribosomes on the ER arrange amino acids to produce a specific protein.
DNA → mRNA → ER/ribosomes → amino acids → protein

Thyroid gland

secrete thyroxine (T4) which stimulates metabolism in cells

Incr vs dcr lvls of hormone

Incr = speed up metabolism (incr energy/wt loss)

Dcr = slow metabolism (sluggish & weight gain)

Muscle cell

Long & slender, contains fibers that aid in contracting & relaxing

Epithelial cell

(a lining & skin cell) may be square & flat to provide protection

Nerve cell

Long & have various fibrous ext that aid in its job of carrying impulses

Fat cell

Large, empty spaces for fat storage

Differentiation

Describes the change in cells as they mature and specialize

Tissue

Group of similar cells working together to do a specific job. Same types may be found all over body

Histologist

Scientist who specializes in study of tissues

hist/o

tissue

4 types of tissues

epithelial, muscle, connective (fat), nerve