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Flashcards in Chapter 4 Deck (50)
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1

DNA stands for

deoxyribonucleic acid

2

DNA components

sugar: deoxyribose
phosphate group
nitrogenous base: adenine

3

Purines vs Pyrimidines

purines: A & G (double ring)
pyrimidines: T & C (single ring)

4

each sidepiece is a backbone composed of ____ groups and ______

phosphate;deoxyribose

5

what are the nitrogenous bases united by?

hydrogen bonds

6

genetic instructions for synthesis of proteins

genes

7

fine filamentous DNA material complexed with proteins

chromatin

8

histones (2)

-disk shaped clusters of proteins
-what DNA molecules wind around

9

histones are divided into ______

nucleosomes

10

2 parallel filaments of identical DNA

sister chromatids

11

what joins two chromatids together

centromere

12

RNA vs DNA (4)

RNA: 1 nucleotide; DNA: 2 nucleotides
RNA: ribose DNA:deoxyribose
RNA:uracil instead of thymine
RNA: smaller

13

3 types of RNA

mRNA
tRNA
rRNA

14

what determines the nucleotide sequence in the DNA

the amino acid sequence

15

how many chromosomes do humans have?

46 chromosomes: 23 pairs

16

3 stop codons

UGA, UAG, UAA

17

start codon

AUG

18

a sequence of 3 nucleotides that stands for one amino acid

base triplet

19

T/F all body cells contain identical genes, except sex cells & immune cells

TRUE

20

when a gene is activated what is made?

mRNA

21

in transcription DNA codes for____; while mRNA codes for protein during ______

mRNA; translation

22

enzyme that binds DNA and assembles mRNA. what signals this enzyme?

RNA polymerase; TATATA

23

exons are ____ while introns are ____

sense (spliced together); non sense

24

who are the 3 participants in translation?

mRNA, tRNA, rRNA

25

what binds mRNA?then what?

small sub-unit then the large sub-unit binds the small sub-unit

26

where does tRNA pick up the anticodon for translation?

from free amino acids in the cytosol

27

where are proteins headed for lysosomes or secretion made?

ribosomes or rough ER

28

is protein synthesis finished once the amino acid sequence is made? what has to happen?

no, the protein is functional only after it is coiled and folded into a precise secondary or tertiary structure

29

chaperones

old proteins that help new proteins in folding into the proper shapes

30

what is an example that can determine if a gene is turned on or off?

hormones